Vectorial noncovalent synthesis of bendable organic crystals through dynamic dislocation

Domain: neuroscience
Published: 2026-01-22
Editorial outcome: major_revision

Abstract
Organic molecular crystals with controllable bending angles are crucial interconnectors in integrated optoelectronic chips, which can precisely guide optical signals along a predetermined path to achieve effective optical path steering. Nevertheless, current methods of tailoring molecular crystals with desired bent geometric features yet without fractured bending interface has not yet been fully realized. Here, we addresses this issue by proposing a universal “molecular cocrystal” strategy that introduces directional charge-transfer non-covalent interactions into molecular systems to weaken the original interactions, thereby triggering the spontaneous deformation transition from crystal slippage to bending. Significantly, a diverse range of self-assembled bent crystals with accurate angles ranging from 61.8° to 85.0° have been synthesized without destroying the structural integrity of the crystals. The proposed strategy is also applied to construct hierarchical bent microstructures with 2 to 6 bends. These as-prepared bent crystals exhibit excitation position-dependent anisotropic optical behaviors, which are applied into the photonics switch with adjustable on/off ratio. This methodology offers a versatile pathway to purposely design bent crystals with tailored angles, thereby laying a structural foundation for the on-chip organic optoelectronics.

Introduction
Organic molecular semiconductor crystals based on molecules arranged into organized structures via weak intermolecular noncovalent interactions, including hydrogen bonds, π–π interactions, charge transfer (CT) interactions, and van der Waals forces, have attracted increasing attention in recent years due to their considerable scientific and technological significance1–3. The controllable preparation of crystals with specific geometric characteristics is one of the prerequisites for applying these organic materials within advanced optoelectronic applications, such as photodetectors4,5, field-effect transistors6,7, light-emitting diodes8,9, and solid-state lasers10,11. Impressively, the bent crystal possesses the capability to not only guide the optical signals to propagate along the predetermined path to achieve effective steering of the optical path12, but also to further modulate the transmission characteristics of optical signal, such as phase and polarization state, through the refinement of its geometry and material attributes13,14. This dual capacity to control the transmission path and transmission characteristics of optical signals significantly enhances the flexibility and designability of photonic integrated systems15–17. As a representative case, organic crystals composed of (Z)−4-(1-cyano-2-(4-(dimethylamino)phenyl)vinyl)benzonitrile with multiple crystal-bending modes under external stress and hydrochloric acid atmosphere, display active low-loss optical waveguide properties with different curvatures in the bent state18.

Significantly, the limited resources and complexity of system layout in micro/nanoscale integrated photonics circuits pose serious challenges to the effective management of optical signals19,20. Consequently, the capability to flexibly adjust the direction of optical signals emerges as paramount for achieving efficient and accurate connection of the optical path21. To date, considerable efforts have been devoted to developing strategies for fabricating bent organic crystalline materials that respond to external stimuli22,23. However, the application of mechanical stimulation, such as curving or twisting, often induces stretching or compression of molecular arrangements at the curved interface (left of Fig. 1A)24–26, which can compromise structural integrity and degrade optical performance. Moreover, maintaining both structural stability and functional integrity in low-ductility organic molecular crystals during deformation remains particularly challenging. Owing to their limited tolerance to stress and strain, such crystals are prone to cracking or loss of functional properties under mechanical force27,28. It is therefore imperative to develop effective methods for achieving and stabilizing crystal deformation to advance applications in micro/nanoscale integrated photonics29.

In this study, we demonstrate the spontaneous bending of organic crystals with well-defined bending angles, without applying external mechanical force (as illustrated on the right side of Fig. 1A). This behavior is achieved through a cocrystal engineering strategy that introduces directionally distinct noncovalent interactions. As illustrated in Fig. 1B, a system based on a single polycyclic aromatic hydrocarbon molecule with isotropic intermolecular interactions (where E1 ≈ E2) tends to self-assemble into 1D or 2D micro/nanostructures along the directions governed by these interactions. The introduction of electron-withdrawing cyanide groups breaks this isotropy, creating anisotropic interactions (i.e., E New > E Original). In the newly formed cocrystals, the non-covalent intermolecular interactions along the orthogonal direction are weakened due to the high temperature of the substrate, which was maintained at 30°C using a temperature controller. This thermal effect induces a slip deformation within the crystal structure. The subsequent continuous growth of molecules at both ends of the slipped microstructure increases stress on the slipping interface. This buildup of stress is ultimately relieved by spontaneous rotation, leading to the observed crystal bending. Impressively, this strategy has demonstrated a universality in a wide range of cocrystal systems, successfully achieved the fabrication of bent crystals with different luminous colors covering the bending angle range from 61.8° to 85.0°. In addition, the proposed strategy is applied to construct hierarchical bent microstructures with 2 to 6 bends. Notably, the bent microstructure with anisotropic optical properties is demonstrated to provide a photonic switching functionality, featuring an adjustable on/off ratio spanning from 2.6 to 12.2. The proposed directional noncovalent interaction strategy provides methodological guidance and material foundations for developing complex low-dimensional structures required for practical applications in integrated optoelectronic chips.

Results
Directional noncovalent interaction strategy
The present work employs polycyclic aromatic hydrocarbon perylene as the representative electron donor (denoted as donor 8) and 2,4,6-trimethylbenzene-1,3,5-tricarbonitrile (TBT) as the electron acceptor (denoted as acceptor 11). Using a typical solution evaporation method30–32, the two components were co-crystallized from a dichloromethane (DCM)/ethanol (EtOH) mixture (2 mmol L⁻¹) on a substrate maintained at 25°C, yielding smooth-surfaced one-dimensional structures (Supplementary Fig. 1). Detailed experimental procedures and the resulting crystal structures are provided in the Supplementary Information. The obtained crystallographic data (Supplementary Table 1) reveals that the perylene-TBT cocrystal (cocrystal 8&11) possesses a triclinic structure. As shown in Supplementary Fig. 2, the cocrystal 8&11 exhibits anisotropic noncovalent interactions, featuring strong charge-transfer character along one direction and weaker π–π stacking in the orthogonal direction. Notably, we observed that when the substrate temperature was raised to 30°C, a slip line appeared within the crystal (Supplementary Fig. 3).

The Supplementary Movie 1 captured via fluorescence microscopy (FM), clearly shows the existence of slip lines during crystal growth and solvent evaporation, and then leads to the spontaneous crystal bending. The self-assembly bending process is further illustrated schematically in Fig. 1C and through the corresponding bright-field images captured over time, which are presented in Fig. 1D1–D4. During the self-assembly bending process, the crystal is induced into a slipped state before 1.09 s, subsequently undergoing bending through a rotation to an angle of ~155° at 1.11 s, after which the bending angle gradually decreases to ~148° at 2.06 s. This continuous bending process demonstrates that the crystal is a single entity, thereby excluding the possibility of epitaxial growth between two separate crystals.

The self-assembly bending process operates via a supersaturation-controlled strategy33,34, wherein the concentration of the mixed solution plays a crucial role. As shown in Supplementary Fig. 4, at a relatively low mixture concentration of 2 mmol L−1 and high temperature substrate of 30°C, cocrystal exclusively in slipped state, without the presence of bending microrods. However, as the solution concentration increases, the influence of supersaturation on the morphology of molecular crystals becomes increasingly apparent. Specifically, the proportion of slippage microrods decreases gradually as the solution concentration increases, while the proportion of bending microrods increases correspondingly. When the solution concentration reaches 5 mmol L−1, and the bending microstructures dominate the crystal form. This phenomenon is ascribed to the high-concentration solvents that cause the continuous growth of molecules at both ends of the slippage microstructures, in which generates interfacial stress on the slip surface35. In order to relieve the stress and reach a thermodynamically stable state, the slippage crystals are spontaneously bent through rotation process36.

The proportion of DCM in the mixed solvent (DCM/EtOH) to the morphology of the microstructures provides further evidence that the bending structure exhibits greater thermodynamic stability. Specifically, at a constant high solution concentration of 5 mmol L−1 with a relatively low proportion of DCM, the volatile speed of the DCM/EtOH solvent is relatively slow due to the volatility of EtOH. Therefore, the self-assembly process is mainly dominated by the high solution concentration (i.e., the thermodynamic factor), which eventually initiates the formation of thermodynamically stable bent microstructures (Supplementary Fig. 5A). As the proportion of dichloromethane (DCM) gradually increases, the bent microstructures transform into shorter and thicker forms, while long and thin rod-like structures emerge simultaneously (Supplementary Fig. 5B). Additionally, when the DCM proportion exceeds 60 vol%, the volatile speed of the mixed solvent becomes relatively rapid. Consequently, the self-assembly process is primarily influenced by the evaporation rate (i.e., the kinetic factor), ultimately leading to the formation of dynamically stable slipped rod-like structures (Supplementary Fig. 5C–E). The thermodynamic stabilities of the bent microstructures and slipped microrods were analyzed based on the feasible activation barriers and free energy of crystals depicted in Supplementary Fig. 5F. The results indicate that the bent microstructures exhibit greater thermodynamic stability compared to the slipped microrods (i.e., G V < G R). Furthermore, the activation barrier of the bent microstructures is higher than that of the slipped microrods, and a higher mixture cocrystal solution concentration is therefore required to surmount this barrier37.

The imaging and analysis of a typical 8&11 slipped cocrystal are presented in Fig. 2A–D. The representative scanning electron microscopy (SEM) image depicted in Fig. 2A reveals a distinct slipping interface, which is further accentuated in the TEM image presented in Fig. 2B, showing the 73.8° slipping angle. In addition to the experimental results, theoretical analysis also supports that the temperature-induced slipping process is ascribable to the relatively weak interactions within the crystal plane with the largest interlayer spacing, i.e., the plane with the weakest interlayer interactions. Specifically, the simulated growth morphology of the cocrystal 8&11 (Supplementary Fig. 6A) allowed to identify the (001) crystal plane as the one with the largest interlayer spacing (Supplementary Table 2). Combining the simulated growth morphology with XRD data, we further confirmed that the crystal’s top surface corresponds to the (110) crystal plane (Supplementary Fig. 6B). The theoretical dihedral angle between the (001) and (110) crystal planes was calculated to be 73.5° (Supplementary Fig. 6C), which is in close agreement with the actual bending angle of 73.8° observed in the cocrystal 8&11. Consequently, slippage occurs along the [100] direction at relatively high temperatures (Fig. 2C). The slip angle distribution of microrods derived from an analysis of TEM images indicates that the slipping angles deviated symmetrically about an average value of 73.6° (Fig. 2D). Notably, the difference area of the shared interface with the ratio of α1/α2 = 0.98 was attributed to asymmetric solute deposition resulting from the concave substrate. This asymmetric area creates an interfacial stress38, as illustrated in Fig. 2B and Supplementary Fig. 7. Consequently, both ends of the slipped rod-like microstructure continue growing until the slipped microstructure gradually rotates by 180° and bends to release interfacial pressure (Fig. 2B, F).

The imaging and analysis of a typical bent cocrystal 8&11 are presented in Fig. 2E–H. The representative SEM image (Fig. 2E) indicates that the bent microstructure displays a bending angle of 73.8°, which is further shown by the corresponding TEM image (Fig. 2F). Furthermore, the bending angle is consistent with the observed slip angles (Fig. 2B, D), confirming that the microstructure underwent a 180° rotation prior to bending. The schematic illustrating the proposed rotation and bending mechanism is presented in Fig. 2G. The bending angle distribution of microrods in Fig. 2H indicates that the dihedral angles between the (001) and (110) planes deviated asymmetrically about a modal value of 73.8°, which is basically consistent with the ideal bending angle of 75.8° between the (110) and (001) planes (inset of Fig. 2H). To ensure our analysis is representative and reproducible, we randomly selected areas from several independently prepared samples, as shown in Supplementary Fig. 8, a large number of bent microstructures with the angle of 146–148° are distributed in different areas of substrate. Meanwhile, the optical images of cocrystal 2&11 before and after bending further demonstrate how the rotation and bending of the slipped crystals release interfacial strain (Supplementary Fig. 9). The SEM images further confirmed the consistency of the slip plane and the bending plane (Supplementary Fig. 10).

Impressively, the continuous process from slippage to bending is visually demonstrated by molecular dynamics simulation39. As shown in Supplementary Fig. 11A, donor and acceptor molecules aggregate under the charge transfer interaction to form a stable rod-like crystal nucleus within 20 ns. However, the charge transfer interaction is disturbed by the increasing temperature of the system, which leads to the initial slip phenomenon in the crystal nucleus, and results in the energy of the system increases significantly within 20–40 ns. With the further ordered rearrangement and aggregation of molecules at the sliding interface, metastable sliding rod-like crystals are gradually formed. It is worth noting that the crystal of this slippage structure is not in the lowest energy stable state. Therefore, when the molecules continue to aggregate at both ends of the rod-like structure until the stress on the sliding plane reaches a critical threshold, the slippage crystal will bend through the rotation mechanism to release the stress. As shown in Supplementary Fig. 11B, slight rotations of the slippage crystal significantly reduce the energy of the system within about 20 ns. Subsequently, after a position relaxation of the regions at both ends of the slippage structure, it rotates rapidly, eventually forming a thermodynamically stable bent crystal structure.

Universality of directional noncovalent interaction strategy
The results depicted in Fig. 3 demonstrate that the directional noncovalent interaction strategy can be applied into a diverse array of molecular systems, including donors 1–9 and acceptors 10–13 (Fig. 3A). This strategy effectively controls the slipping, rotation, and bending mechanisms within cocrystal systems at relatively a high temperature substrate, as demonstrated by the corresponding FM images presented in Fig. 3B–L. The introduction of either electron acceptor into one of the series of electron donors resulted in slippages within the 1D cocrystals (Fig. 3B1–L1), and the corresponding self-assembly processes yielded bent crystals, characterized by sharp boundaries between domains and bending angles that ranged from 61.8° to 85.0° (Fig. 3B2–L2). The detailed crystallographic parameters were presented in Supplementary Tables 3–12 and Supplementary Fig. 12. The simulation results were further applied to develop the schematics presented in Fig. 3B3–L3 illustrating the spatial relationships between the respective bending planes. As observed for cocrystal 8&11 in Fig. 2C, the temperature-induced slipping process in these cocrystals consistently occurs within the planes exhibiting the largest interlayer spacing. This mechanism has been further confirmed across multiple organic crystals (Supplementary Figs. 13, 14). The reason for the crystals undergoing slippage at elevated temperature can be evaluated in greater detail according to schematics illustrating the noncovalent interactions within cocrystal 3&11 shown in Fig. 3M. The newly introduced acceptor molecule in the 3&11 cocrystal system forms anisotropic intermolecular interactions involving a strong charge transfer (CT) interaction with an energy of E New = −20.7 kcal mol-1 with the donor molecule, which weakens the original intermolecular interaction to relatively weak π-π interactions with an energy of E Original = −2.5 kcal mol−1. Consequently, the microcrystal undergoes slipping, rotation, and bending along the weaker interaction associated with the (001) crystal plane (Fig. 3D1–D2). The magnitudes of noncovalent interactions presented in Fig. 3N (also refer to Supplementary Figs. 15–24) further validate the propensity of cocrystals to slip, rotate, and bend in response to their relatively weaker interactions following the introduction of a stronger interaction. The central emission wavelength of these cocrystals spans from 420 to 760 nm, with the corresponding Commission Internationale de l’Éclairage (CIE) coordinates close to that of pure blue, green and red light (Fig. 3O and Supplementary Fig. 25), respectively. Furthermore, the results from thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), reveal that typical slipped and bent cocrystals do not exhibit any prominent peaks (Supplementary Fig. 26), suggesting that this spontaneous deformation process does not involve a phase transition40.

Hierarchical bending effect
The proposed self-assembly process based on directional noncovalent interactions was subsequently applied to fabricate multiple hierarchical bending configurations. As illustrated in Fig. 4A, hierarchical 2-bend microcrystals were successfully synthesized on a substrate maintained at 32°C, yielding the distinct 2-slip and 2-bend configurations (Fig. 4B, C), respectively. Real-time FM visualization of the 2-slip and 2-bend assembly processes is presented in Supplementary Movie 2. These processes can be summarized using the bright-field SEM images shown in Fig. 4D–F, where the continuous growth at both ends of the slipped structure induce rotation as the stress on the sliding plane gradually increases, and the stress is released rapidly within 0.04 s through the bending of the slipped crystal. The representative SEM image in Fig. 4G (see also Supplementary Fig. 27) and the TEM image in Fig. 4H clearly show that the 2-bend microstructure possesses equivalent angles of 73.8° between the trunk and slip planes. Additionally, FM images of the as-fabricated hierarchical microstructures with 3-bend, 4-bend, 5-bend, and 6-bend configurations (Fig. 4I–L), obtained at temperatures of 34, 36, 38, and 40°C respectively (Detailed experimental procedures are provided in the Supplementary Information.). A schematic representation of the temperature-triggered self-assembly slipping process and the concentration-driven self-assembly bending process is provided in Supplementary Fig. 28.

Anisotropic optical waveguide applications of bent molecular crystals
Anisotropic optical waveguides not only facilitate the asymmetric transmission and power distribution of optical signals but also introduce an innovative approach for optical communication and information processing, thereby carrying significant importance within the realm of optoelectronics technology41,42. Given the paramount importance of developing organic micro/nanostructures that facilitate anisotropic photonic transmissions, we conducted the photonic performance of a typical bent cocrystal 8&11, serving as an anisotropic optical waveguide. This evaluation was carried out using a home-made micro area photoluminescence (μ-PL) optical microscope equipped with a laser light source operating at a wavelength of 375 nm (Supplementary Fig. 29)43. As shown in Fig. 5A, the bent microstructure comprises two approximately equal-length sections, A and B, measuring 50.7 μm and 50.3 μm, respectively. When laser excitation is coupled at the bending terminal-3 (T-3), the resulting FM image in Fig. 5B displays comparable laser emission at both the terminal-1 (T-1) and terminal-2 (T-2) points, suggesting that sections A and B function as active optical waveguides. Furthermore, Fig. 5C1–C5 exhibits FM images obtained by coupling laser excitation at various positions within section A relative to the T-1, T-2, and T-3 points. Similarly, Fig. 5D1–D5 presents FM images captured under coupling within section B at different excitation positions relative to the T-1’, T-2’, and T-3’ points. The propagation distances from the excitation points to T-1 in Fig. 5C1–C5 (labeled as settings I–V) and to T-2’ in Fig. 5D1–D5 (also labeled as settings I–V) are virtually identical. Figure 5E, F displays the PL spectra recorded at T-1 when laser excitation is coupled within section A and at T-2’ when laser excitation is coupled within section B, respectively. The results presented in Fig. 5E, F were employed to determine the propagation losses for light traveling a distance x through sections A and B, according to the corresponding PL intensity ratios I tip/I body in Fig. 5G, where I tip and I body represent the PL intensities measured at the emitting terminal and the excitation body of the bent microstructure, respectively. Subsequently, the propagation loss curves were determined by fitting the experimental results to the exponential function I tip/I body = A exp(−Rx)44, with A being the ratio I tip/I body at x = 0 and R denoting the waveguide loss coefficient in µm−1. Converting the obtained values of R to units of dB µm−1 yielded 0.0521 dB µm−1 for segment A and 0.0534 dB µm−1 for segment B, differing just by only 2.5%. Therefore, the results indicate that optical signals suffered approximately equal energy losses in sections A and B. Conversely, the PL results shown in Fig. 5H reveal a marked difference in the signal intensities collected at T-2 in Fig. 5C1–C5 compared to those collected at T-1’ in Fig. 5D1–D5, despite the equivalent optical path lengths within the bent microstructure. This anisotropy in optical propagation is further reflected by the fact that the intensity of emissions at point T-3 are consistently much higher than those at T-3’. The discrepancy in PL intensities at point T-3 and T-3’ is clarified by plotting these intensities in Fig. 5I. The bottom left inset reveals that the polarization angles (θ) for emissions from sections A and B are respective 100° and 130°, which is consistent with the bending angle of crystal. Meanwhile, the top right inset demonstrates that the bent microstructure exhibits a significant photonic switching functionality, with ON/OFF ratios ranging from 2.6 to 12.1 achieved at the micro/nanoscale by utilizing different excitation positions as control inputs, which is crucial for the advancement of integrated optoelectronic circuits.

The anisotropic optical propagation phenomenon observed in the bent crystals 8&11 is mainly attributed to the change in the direction of the transition dipole moment (TDM). Specifically, photons tend to propagate along the direction perpendicular to the TDM, and the direction change is shown in Fig. 5J. This issue was investigated based on the results obtained from time-dependent density functional theory (TDDFT) calculations (Supplementary Fig. 30A). The calculations revealed that the TDM of cocrystal 8&11 were oriented at an angle of 12.0° between molecules 8 and 11. When considered in conjunction with the molecular packing mode, the TDM were found to be oriented at an angle of 47.0° relative to the [010] growth direction (Supplementary Fig. 30B). Consequently, light originating from T-1 tends to propagate upwards towards the top surface, whereas light from T-2’ is inclined to propagate downwards towards the bottom surface (Fig. 5J). This directional difference arises because section B was rotated by 180° prior to the bending process. The results displayed in Fig. 5I provide evidence supporting the proposed rotation of the slipped microcrystal.

Methods
Synthesis of hierarchically slipped microcrystals
A solution of acceptor and donor molecules (1:1 molar ratio) in DCM was prepared with a concentration of 2 mmol L⁻¹. Then, 10 mL of this stock solution was rapidly injected into 10 mL of EtOH. Immediately, 200 µL of the resulting mixture was drop-cast onto a pre-heated quartz substrate using a micropipette. The substrates were maintained at precise temperatures of 30 ± 0.2°C and 32 ± 0.2°C, respectively, using an electric temperature control platform. After complete solvent evaporation (typically within 5–7 min), the resulting microstructures were characterized. The slight difference in substrate temperature (30 vs. 32°C) fine-tuned the self-assembly kinetics, leading to microcrystals with distinct single-slip (1-slip) and double-slip (2-slip) configurations, respectively.

Synthesis of hierarchically bent microcrystals
A more concentrated stock solution (5 mmol L⁻¹ in DCM, 1:1 molar ratio of acceptor/donor) was used. Similarly, 10 mL of this solution was injected into 10 mL of EtOH. The mixture was drop-cast onto quartz substrates maintained at a series of precisely controlled temperatures: 30, 32, 34, 36, 38, and 40°C (±0.2°C). After complete solvent evaporation, microstructures identified as 1-bend, 2-bend, 3-bend, 4-bend, 5-bend and 6-bend were observed on the respective substrates.

Data availability
All data generated in this study are provided in the paper or Supplementary Information. All data are available from the corresponding author upon request. The X-ray crystallographic coordinates for structures reported in this study have been deposited at the Cambridge Crystallographic Data Centre (CCDC), under deposition numbers: 2141808; 2288478; 2288480; 2288481; 2288619; 2288482; 2334148; 2288488; 2334145. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "Wang and co-workers reported a novel strategy that employs directional interactions to weaken the original ones, thereby inducing the crystal to transition from a slipped to bent state. This approach has exhibited a universality in a wide range of cocrystal systems, enabling the successful fabrication of bent crystals in a variety of luminous colors, with bending angles ranging from 61.8° to 85.0°. Notably, this strategy has also been effectively utilized to construct hierarchical bent microstructures. Given that these bent microstructures possess anisotropic optical properties, the team has successfully demonstrated their potential for photonic switching functionality. This study opens up a new avenue in the field of organic crystal engineering, the potential of the reported method of crystal preparation and the crystals themselves can be quite interesting to the general chemistry community. I recommend acceptance of the manuscript after the minor issues and comments below have been addressed in full:\n1.In this paper, given the crystallographic parameters and crystal structure have been clarified, it is necessary to provide detailed information about the preparation of bulk crystals suitable for X-ray single crystal diffraction analysis next.\n2.In this work, theoretical calculations method of the crystal structure in Figure 2 and detailed structural characterization should be explained.\n3.How about the thermal stability of the bent structures?\n4.The illustrations in Figures 2b and 2f should be rearranged so that their angles match those of the experimental evaluation objects.\n5.The authors should provide the spectrum shown in Figure 3o.\n6.The author analyzed the transition dipole moment of the cocrystal. However, why did the experimental results in Figure 5 show that the directions of the transition dipole moments at the two ends of the bent structure were different?", "reviewer_2": "The manuscript by Ma et al demonstrates the emergence of a route to grow molecular crystals that are inherently bent. The team presents evidence that the degree of bending can be tuned by changing the characteristics of the crystallisation procedure, including through change in the rate of crystallisation and the saturation levels. The team proposes a mechanism for the bending of the crystal as being due to an inherent desire to reduce interfacial strain energy, for which they have sought support through some molecular dynamics simulations. The authors subsequently demonstrate how multiple bends can be introduced into the same crystal, leading to extended hierarchical constructions. Finally, the authors provide some evidence that the bent crystals can be used as optical waveguides, suggesting that these bent crystals could be suitable in nano-optical devices. In principle the study is an interesting concept with potential to out-compete the need to develop mechanically flexible crystals for this purpose. The ability to selectively grow bent crystals, rather then bend crystals mechanically, could lead to higher integrity in the optical components.\nThe study seems generally to be well documented with some convincing measurements and analysis of the crystal structure and behaviours. However, the paper is itself quite a difficult read, making it somewhat challenging to fully follow the logic that is being presented. Clarity needs to be significantly improved prior to any publication. In particular, it is quite difficult to follow what the model actually is (seemingly dubbed slip-rotation). I am also uncertain as to the reproducibility or generality of many of the datasets being presented. For example, in the microphotographs (and associated discussions) on the ‘proportion of slip vs bent’ crystals, there is no indication as to how representative the small area of analysis is, how reproducible the proportions are, or even what the relative proportion are (noting that each analysis is done on drastically different numbers of crystals). The same holds true for the crystal angles being measured/presented for the different types of crystals/bent states: how meaningful are these angles, or do they vary between crystals?\nThe data availability statement indicating that data are available from the authors on request is extremely disappointing. I would strongly encourage the authors to ensure that the data are available with publication in support of open science, especially if they aim to publish in a high impact journal where results should be open to scrutiny. This is particularly true given the low level of data presented in the ESI and main manuscript, especially around the simulations, where no information is actually available on their outputs.\nIn addition to these broader criticisms, I would like the authors to strongly consider a number of additional points, which I summarise here in order of reading:\n- In the introduction (p2) the authors write about a ‘spontaneous transition from slippage to bending’. At this point of the manuscript it is not clear what this means.\n- In the introduction the authors discuss a strategy towards self-assembled crystals to induce spontaneous transition from slippage to bending without destroying the crystal integrity. It is not clear what this means, or what is being criticised here. There are many mechanically flexible, plastic, etc crystals that bend without affecting the overall integrity of the crystal, and which do not affect the optical wave guiding nature of the crystals.\n- The authors write ‘’ upon a substrate with a relatively high temperature of 30 ℃,’’ but it is not clear what the meaning is.\n- It is not clear what mechanism the authors are proposing when they write: ‘’The continuous growth of the assembled molecules at both ends of the slippage microstructure causes the stress on the slipping surface to increase continuously, ultimately leading to spontaneous rotation as a means of stress relief’’ or when they propose ‘’ proposed in this work undergoes a controlled bending at a specific angle through a rotation process, maintaining its original molecular arrangement without undergoing stretching or compressive deformation (as illustrated on the right side of Figure 1A’’. I think it is particularly difficult to understand what is being proposed as the model the authors seem to be contrasting in Figure 1A is an old (and out-dated) model that is proposed for mechanical bending of crystals, but the present manuscript discusses growth of bent crystals; not post-growth bending. This is a confusing comparison\n- The authors have suggested that ‘’ The detailed experimental procedures along with the resultant crystal structures are presented in Supplementary Materials’’ However no such details are actually given.\n- In Figure S3, the predicted morphologies are absolutely not consistent with the morphologies observed by microscopy. The simulated morphologies are block-like, whilst those observed experimentally are rods. It is not clear what the 3 different figures in S3 refer to. The same holds for all later morphology predictions as well.\n- In Figure S5 it is not clear what feature the authors are referring to as being indicative of slip. The same shadowing is seen in the ‘non-bent’ crystal in S5. A similar confusion is around Figure S11 and the insets.\n- Video S1 certainly shows that the crystal bends during evaporation of solvent, but it is not clear how the video suggests evidence of a slip-bend mechanism.\n- In S6 the authors are comparing ratios alpha 1 and alpha 2. These measurements are done manually on a TEM figure, but there is no indication of the accuracy or reproducibility of these measurements, or associated errors. It is difficult to be convinced that the very small offset is real, rather than an aberration, slip of the hand during measuring, or even due to some small crystal fragment agglomerating to the side of the larger crystal.\n- Throughout the manuscript, there is no discussion around whether the ‘bent’ crystals are in fact a single crystal, or if they result from agglomeration of two crystals through a disordered interface. What evidence do the authors have for the bent crystals being a single crystal?\n- In Figure S11 it is not clear if the pre- and post-bent crystals are the same crystal. If not, how useful is the comparison?\n- I am quite confused about the comparison of ‘simulated’ and experimental PXRD patterns in the ESI for the range of cocrystals. First, it is not clear where the experimental or simulated data came from. Second, it is quite concerning that for almost none of the crystals do the experimental and simulated data match. This suggests a potentially significant error in the data, or perhaps that powder diffraction was measured on single crystals (but why?), which results in major texturing. This needs to be explained.\n- It is unfortunately impossible to comment on the molecular dynamics trajectories in the present case, given the lack of analysis presented in the current manuscript, aside from some difficult-to-understand snap shots. Moreover, it is odd to see such smooth energy profiles unless there is some significant steering in the MD trajectories. If the authors are going to present MD data, there needs to be much more analysis (e.g. some analysis based on RDFs and cluster growth analysis, free energy analyses, etc) that could bother clarify the nature of the study that was done, and also lend some quantification to the data sets.\n- The experimental and simulation details are far from being sufficient to understand, let alone reproduce, the results in the paper. There is little-to-no description of how the multiple hierarchical bends were introduced into the crystals\n- Stating simulations were performed ‘by materials studio’ is not sufficient. What algorithms were used, and what were the settings? Moreover the authors need to clarify that they did not perform crystal structure prediction, but rather crystal morphology predictions. It is not clear how the authors have modelled their crystals using Gaussian16 (a gas phase code), or what these simulations actually were. It is not clear what algorithm was selected to drive nucleation in MD simulations; nucleation being a rare event usually needs a bias in the simulations so I presume something similar was needed here. One would not normally expect an NVT simulation to result in nucleation/crystal growth unless a driver or other thermodynamic trajectory were to be introduced into the simulation (e.g. slowly remove solvent molecules, drive temperature, etc). See e.g: doi/10.1002/wcms.1697."}, "author_response": "S] _j]Yldq Yhhj][aYl] l`] j]na]o]j„k professional comments and feedback to help us further perfect our work. According to your instructive suggestions, we have made extensive corrections and performed supplementary experiments to our previous manuscript. The detailed point-by-point responses to l`] j]na]o]jk„ [gee]flk Yj] Yk follows. We believe that the revised version is satisfactory for publication in Nature Communications.\nRevision: All the changes are highlighted in the revised manuscript.\nDetailed point-by-point responses:\n.+ Ef l`ak hYh]j) _an]f l`] [jqklYddg_jYh`a[ hYjYe]l]jk Yf\\ [jqklYd kljm[lmj] `Yn] Z]]f [dYja^a]\\) al ak f][]kkYjq lg hjgna\\] \\]lYad]\\ af^gjeYlagf YZgml l`] hj]hYjYlagf g^ Zmdc [jqklYdk kmalYZd] ^gjT*jYqkaf_d][jqklYd \\a^^jY[lagfYfYdqkak f]pl+\nResponse: Thanks a lot for reminding us of this important point. We have added the preparation of bulk crystals for X-ray single crystal diffraction and related detection method in revised supplemental information. The bulk organic TBT-Perylene cocrystals were obtained via the liquid-liquid diffusion method. In a typical experiment (J. Am. Chem. Soc. 2023, 145, 9285), 0.1 mmol TBT and 0.1 mmol Perylene were dissolved into 10 mL dichloromethane (DCM) at concentration of 10.0 mmol L(cid:141)1 within a sample bottle at room temperature. Second, 20 mL of ethanol was added directly onto the stock solution to create a distinct layer between the two liquid levels, and then stand for three days. Finally, the TBT-Perylene cocrystals were obtained as the constantly solvent evaporated.\nSingle crystal data were obtained by the single crystal X-ray Diffraction (SCXRD) analysis. X-ray diffractions was carried out at 170 (2) K on a Bruker D8 VENTURE diffractometer using Mo-G‘ jY\\aYlagf 'J = 0.71073 Å). Integration and scaling of intensity data were performed using the SAINT program. Data were corrected for the effects of absorption using SADABS. The structures were solved by direct method and refined with full-matrix least-squares technique using SHELX-2014 software. Non-hydrogen atoms were refined with anisotropic displacement parameters, and hydrogen atoms were placed in calculated positions and refined with a riding model. The molecular structure and configuration are analyzed by importing the corresponding CIF file into the Mercury software. The simulated growth morphology and crystal facet parameter are conducted based on single-crystal data by the Materials Studio software package. The PXRD patterns were measured through a D/max 2400 X-ray \\a^^jY[lge]l]j oal` ?m G‘ jY\\aYlagf 'J = 1.54050 Å( gh]jYl]\\ af l`] /“ jYf_] ^jge 2y to 40°.\nRevision: We have added the corresponding hYjY_jYh` (cid:129)P`] Zmdc gj_Yfa[ P>P-Perylene cocrystals were obtained via the liquid-daima\\ \\a^^mkagf e]l`g\\~8 Oaf_d] crystal data were obtained by the single crystal X-jYq@a^^jY[lagf'O?TN@(YfYdqkak~‚ on the page S2 and S4 in the revised supplemental information. The corresponding reference (J. Am. Chem. Soc. 2023, 145, 9285) has been added on the page 31 in the revised supplemental information.\n/+ Ef l`ak ogjc) l`]gj]la[Yd [Yd[mdYlagfk e]l`g\\ g^ l`] [jqklYd kljm[lmj] af Ba_mj] / Yf\\ \\]lYad]\\kljm[lmjYd [`YjY[l]jarYlagfk`gmd\\Z] ]phdYaf]\\+\nResponse: Thanks a lot for reminding us of this important point. We have added the theoretical calculations method and detailed structural characterization in revised supplemental information.\nMolecular dynamics simulations were performed with the Forcite software package. The Universal Forcefield (UFF)1 was used as the energy expression of phase energy surface (PES). The Qeq method2 was applied to assign the atomic charge with the tolerance of 5×10-4 e. The non-bond interaction was evaluated by the Ewald method3 with the Ewald accuracy of 10-5 kcal/mol. During the optimization process, all the atoms were allowed to relax. The convergence criteria for energy change are 2×10-5 kcal/mol and for force is 0.001 kcal/mol/Å. After the geometry optimization, a 1 ns of NVT MD simulation was performed. The data was collected in the production phase for 90 ns. The Andersen method4 was used to maintain the temperature during the simulation. In our simulations, a gentle traction force (a very small resonant force) was applied to facilitate the initial formation of the crystal nucleus.5 The equilibrium position for the traction force was set at an interplanar distance of 3.65 Å. At this distance, the traction force is zero, and an attractive force is applied at distances greater than this value. The force constant was set to a small value of 0.0572 kcal/(mol·Å2). The key parameters of equilibrium position and force constant for this bias were derived from quantum chemical calculations to ensure physical relevance, which provides a slight thermodynamic driving force to promote nucleation, while being weak enough lg eafaear] h]jlmjZYlagf g^ l`] kqkl]e„k fYlmjYd \\qfYea[k Yf\\ Ynga\\ afljg\\m[af_ fgf-physical artifacts into the simulation trajectory.\nThe SEM images of the samples were obtained by a FESEM, Carl Zeiss, Supra 55 at acceleration voltages of 20 kV. The TEM images were observed by a transmission electron microscopy (FEI company, Tecnai G2 F20, United States). The solution was dropped on a carbon coated copper grid and evaporated. TEM measurement was performed at an accelerating voltage of 120 kV at room temperature. FM images were measured by a fluorescence optical microscope (Leica, DM4000M, Germany) with a spot-enhanced charge couple device (Diagnostic Instrument, Inc). The excitation source is a mercury lamp equipped with a band-pass filter (330-380 nm for UV-light). Single crystal data were obtained by the single crystal X-ray Diffraction (SCXRD) analysis. X-ray diffractions was carried out at 170 (2) K on a Bruker D8 VENTURE diffractometer using Mo-G‘ jY\\aYlagf 'J = 0.71073 Å). Integration and scaling of intensity data were performed using the SAINT program. Data were corrected for the effects of absorption using SADABS. The structures were solved by direct method and refined with full-matrix least-squares technique using SHELX-2014 software. Non-hydrogen atoms were refined with anisotropic displacement parameters, and hydrogen atoms were placed in calculated positions and refined with a riding model. The molecular structure and configuration are analyzed by importing the corresponding CIF file into the Mercury software. The simulated growth morphology and crystal facet parameter are conducted based on single-crystal data by the Materials Studio software package. The PXRD patterns were measured through a D/max 2400 X-ray \\a^^jY[lge]l]j oal` ?m G‘ jY\\aYlagf 'J = 1.54050 Å( gh]jYl]\\ af l`] /“ jYf_] ^jge 2y to 40°. TGA was performed on TA SDT 2960 instrument. The samples were placed in a platinum crucible and heated at a rate of 10 °C/min from room temperature to 500 °C under flowing nitrogen, the temperature at 5% weight loss was regarded as the decomposition temperature. DSC was performed on a TA DSC 2010 during the heating and cooling runs from room temperature to 250 °C with a heating rate of 10 °C/min under nitrogen.\nReferences\n[1] A. K. Rappé, C. J. Casewit, K. S. Colwell, W. A. Goddard III, W. M. Skiff, UFF, a full periodic table force field for molecular mechanics and molecular dynamics simulations. J. Am. Chem. Soc. 1992, 114, 10024(cid:127)10035.\n[2] A. K. Rappe, W. A. Goddard III, Charge equilibration for molecular dynamics simulations. J. Phys. Chem.1991, 95, 3358(cid:127)3363.\n[3] N. Karasawa, W. A. Goddard III, Acceleration of convergence for lattice sums. J. Phys. Chem.1989, 93, 7320(cid:127)7327.\n[4] H. C. Andersen, Molecular dynamics simulations at constant pressure and/or temperature. J. Phys. Chem. 1980, 72, 2384(cid:127)2393.\n[5] A. R. Finney, M. Salvalaglio, Molecular simulation approaches to study crystal nucleation from solutions: Theoretical considerations and computational challenges. Wires. Comput. Mol. Sci. 2024, 1144, e1697.\nRevision: S] `Yn] Y\\]\\ l`] [gjj]khgf\\af_ hYjY_jYh`  Molecular dynamics simulations were performed with the Forcite software package. The Universal Forcefield (UFF)1 was used as the energy expression of phase energy surface (PES). The Qeq method2 was applied to assign the atomic charge with the tolerance of 5×10-4 e. The non-bond interaction was evaluated by the Ewald method3 with the Ewald accuracy of 10-5 kcal/mol~‚ on the pages S3 and S4 in the revised supplemental information. The corresponding references 1-5 hhaavvee been added on the page 3311 in the revised supplemental information.\n0+Dgo YZgml l`] l`]jeYd klYZadalq g^ l`] Z]fl kljm[lmj]k<\nResponse: P`Yfck ^gj j]na]o]j„k comment. Thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC) analytical technique were performed to investigate the thermal stability of bent crystals. As shown in Figure R1A, TGA curve of TBT-Perylene bent microstructures demonstrated the decomposition temperature is 257.99õ+ Bmjl`]jegj]) af l`] hjg[]kk g^ af[j]Ykaf_ l]eh]jYlmj] ^jge - õ lg /23 õ) no obvious peak indicates the occurrence of phase transition (Figure R1B).\nFigureR1.(A) TGA and (B) DSC curves for TBT-Perylene microrods.\n1+P`] addmkljYlagfk af Ba_mj]k /Z Yf\\ /^ k`gmd\\ Z] r]YjjYf_]\\ kg l`Yl l`]aj Yf_d]k eYl[` l`gk] g^ l`] ]ph]jae]flYd ]nYdmYlagf gZb][lk+\nResponse: Thanks a lot for reminding us of this important point. As shown in Figure R2, the illustrations have been rearranged and the angles are matched with those of the experimental subjects.\nFigure R2. (A) Transmission electron microscopy (TEM) micrograph of slipped structure. (B) TEM micrograph illustrating a bending angle of 73.8°.\nRevision: The illustrations in Figures 2B and 2F have been modified as Figure R2 in the revised manuscript.\n22++P`] Yml`gjk k`gmd\\ hjgna\\] l`] kh][ljme k`gof af Ba_mj] 0g+\nResponse: Thanks for your instructive suggestion. The photoluminescence spectrum of cocrystals 3&11, 8&11, and 7&&112 have been added in the revised supplemental information.\n400 600 800\nFigure R3. Spatially resolved PL spectrum of cocrystals 3&11, 8&11, and 7&&112.\nRevision: On page 1100) l`] k]fl]f[] `Yk Z]]f j]nak]\\ Yk  P`] []fljYd ]eakkagf wavelength of these cocrystals spans from 420 to 760 nm, with the corresponding ?geeakkagf Efl]jfYlagfYd] \\] d„w[dYajY_] (CIE) coordinates close to that of pure blue, green and red light (Figure 3o and Supplementary Fig. 24() j]kh][lan]dq+‚ P`] Ba_mj] R3(Supplementary Fig. 24) have been added in the revised supplemental information.\n33++ P`] Yml`gj YfYdqr]\\ l`] ljYfkalagf \\ahgd] ege]fl g^ l`] [g[jqklYd+ Dgo]n]j) o`q \\a\\ l`] ]ph]jae]flYd j]kmdlk af Ba_mj] 2 k`go l`Yl l`] \\aj][lagfk g^ l`] ljYfkalagf \\ahgd] ege]flk Yl l`] log ]f\\k g^ l`] Z]fl kljm[lmj] o]j] \\a^^]j]fl<\nResponse: Thanks for the worth comments. The anisotropic optical propagation phenomenon observed in the bent crystals 8&11 is mainly attributed to the change in ).mron(\nytisnetnI\n3&11\n8&11\n7&12\nWavelength (nm)\nthe direction of the transition dipole moment (TDM). Specifically, photons tend to propagate along the direction perpendicular to the TTDDM. This issue was investigated based on the results obtained from time-dependent density functional theory (TDDFT) calculations (Figure R4A). The calculations revealed that the TDM of cocrystal 8&11 were oriented at an angle of 12.0° between molecules 8 and 11. When considered in conjunction with the molecular packing mode, the TDM were found to be oriented at an angle of 47.0° relative to the [010] growth direction (Figure R4B). Consequently, light originating from T-1 tends to propagate upwards towards the top surface, whereas light from T-/„ ak af[daf]\\ lg hjghY_Yl] \\gofoYj\\k lgoYj\\k l`] Zgllge kmj^Y[] 'Ba_mj] R5). This directional difference arises because section B was rotated by 180° prior to the bending process.The results displayed in Figure 5I provide evidence supporting the proposed rotation of the slipped microcrystal.\nFigure R4. (A) The orientation of the TDM of a cocrystal 8&11 dimer (blue line with arrow). (B) The TDM of the cocrystal 8&11 shows angle of 47.0° with the [010] growth direction.\nFigure R5. The orientation of TDM (top), and its impact on the optical waveguide performance (bottom).\nComments fromReviewer2:\nP`] eYfmk[jahl Zq IY ]l Yd \\]egfkljYl]k l`] ]e]j_]f[] g^ Y jgml] lg _jgo egd][mdYj [jqklYdkl`YlYj]af`]j]fldqZ]fl+P`]l]Yehj]k]flk]na\\]f[]l`Yll`]\\]_j]]g^Z]f\\af_ [YfZ]lmf]\\Zq [`Yf_af_l`] [`YjY[l]jakla[k g^l`] [jqklYddakYlagfhjg[]\\mj])af[dm\\af_ l`jgm_`[`Yf_]afl`]jYl]g^[jqklYddakYlagfYf\\l`]kYlmjYlagfd]n]dk+P`]l]Yehjghgk]k Ye][`Yfake ^gjl`]Z]f\\af_g^l`][jqklYdYk Z]af_\\m]lgYfaf`]j]fl \\]kaj]lgj]\\m[] afl]j^Y[aYd kljYaf ]f]j_q) ^gj o`a[` l`]q `Yn] kgm_`l kmhhgjl l`jgm_` kge] egd][mdYj \\qfYea[„k kaemdYlagfk+P`]Yml`gjk kmZk]im]fldq\\]egfkljYl]`go emdlahd]Z]f\\k[Yf Z] afljg\\m[]\\ aflg l`] kYe] [jqklYd) d]Y\\af_ lg ]pl]f\\]\\ `a]jYj[`a[Yd [gfkljm[lagfk+ BafYddq)l`]Yml`gjk hjgna\\] kge]]na\\]f[]l`Yl l`] Z]fl [jqklYdk [YfZ] mk]\\Yk ghla[Yd oYn]_ma\\]k) km__]klaf_ l`Yl l`]k] Z]fl [jqklYdk [gmd\\ Z] kmalYZd] af fYfg*ghla[Yd \\]na[]k+ Ef hjaf[ahd] l`] klm\\q ak Yf afl]j]klaf_ [gf[]hl oal` hgl]flaYd lg gml*[geh]l] l`] f]]\\ lg \\]n]dgh e][`Yfa[Yddq ^d]paZd] [jqklYdk ^gj l`ak hmjhgk]+ P`] YZadalq lg k]d][lan]dq _jgo Z]fl [jqklYdk) jYl`]j l`Yf Z]f\\ [jqklYdk e][`Yfa[Yddq) [gmd\\ d]Y\\ lg `a_`]jafl]_jalqafl`]ghla[Yd [gehgf]flk+\nResponse: S] _j]Yldq Yhhj][aYl] l`] j]na]o]j„k professional comments and feedback to help us further perfect our work. According to your instructive suggestions, we have made extensive corrections and performed supplementary experiments to our previous manuscript. The detailed point-by-point responses to l`] j]na]o]jk„ [gee]flk Yj] Yk follows. We believe that the revised version is satisfactory for publication in Nature Communications.\nP`]klm\\qk]]ek_]f]jYddqlgZ]o]dd\\g[me]fl]\\oal`kge][gfnaf[af_e]Ykmj]e]flk Yf\\ YfYdqkak g^ l`] [jqklYd kljm[lmj] Yf\\ Z]`Ynagjk+ Dgo]n]j) l`] hYh]j ak alk]d^ imal] \\a^^a[mdl j]Y\\) eYcaf_ al kge]o`Yl [`Ydd]f_af_ lg ^mddq ^gddgo l`] dg_a[ l`Yl ak Z]af_ hj]k]fl]\\+ ?dYjalq f]]\\k lg Z] ka_fa^a[Yfldq aehjgn]\\ hjagj lg Yfq hmZda[Ylagf+ Ef hYjla[mdYj) al ak imal] \\a^^a[mdl lg ^gddgo o`Yl l`] eg\\]d Y[lmYddq ak 'k]]eaf_dq \\mZZ]\\ kdah*jglYlagf(+ EYeYdkg mf[]jlYafYk lg l`] j]hjg\\m[aZadalqgj _]f]jYdalqg^eYfq g^l`] \\YlYk]lk Z]af_ hj]k]fl]\\+ Bgj ]pYehd]) af l`] ea[jgh`glg_jYh`k 'Yf\\ Ykkg[aYl]\\ \\ak[mkkagfk(gfl`]ƒhjghgjlagfg^kdahnkZ]fl„[jqklYdk)l`]j]akfgaf\\a[YlagfYklg`go j]hj]k]flYlan] l`] keYdd Yj]Y g^ YfYdqkak ak) `go j]hjg\\m[aZd] l`] hjghgjlagfk Yj]) gj ]n]f o`Yl l`] j]dYlan] hjghgjlagf Yj] 'fglaf_ l`Yl ]Y[` YfYdqkak ak \\gf] gf \\jYkla[Yddq \\a^^a[mdl fmeZ]jk g^ [jqklYdk(+ P`] kYe] `gd\\k ljm] ^gj l`] [jqklYd Yf_d]k Z]af_ e]Ykmj]\\,hj]k]fl]\\ ^gj l`] \\a^^a[mdl lqh]k g^ [jqklYdk,Z]fl klYl]k7 `go e]Yfaf_^md Yj] l`]k] Yf_d]k) gj\\gl`]qnYjqZ]lo]]f[jqklYdk<\nResponse: Thank you very much for your positive comments on our work and for your insightful suggestions aimed at improving the clarity and robustness of our manuscript. We have thoroughly revised the manuscript to address all the points you raised. We agree that the initial presentation of the core concept could be clearer. In the revised manuscript, we have completely reorganized the narrative to enhance logical flow.\n(1) We now explicitly state our primary objective at the end of the introduction: to demonstrate a general strategy for achieving spontaneous crystal bending by selectively manipulating non-covalent interactions along different crystallographic directions. Regarding the (cid:129)slip-rotation‚ model, we have provided a much clearer and more detailed explanation. We explicitly define the slip state as a key intermediate during the bending process, which is crucial for understanding the mechanism. This intermediate state allows for stress release through molecular slip, facilitating the subsequent rotation and final bent morphology. We have revised the relevant text to illustrate this step-by-step process more intuitively. (2) As you rightly noted, the “slip” state is not a selectively prepared sample, but a transient intermediate captured during the bending process. Its occurrence is intrinsic to the mechanism, and its observation provides key insights into how the bending proceeds. To ensure our analysis is representative and reproducible, we analyzed multiple, randomly selected areas from several independently prepared samples (Figure R1) rather than relying on a single micrograph. As shown in Figure R1, a large number of bent microstructures with the angle of 146(cid:127)148° are distributed in different areas of substrate. In fact, most of the bent microstructures in the field of view are demonstrated to be the realization of scale-up preparation and repeatability, but it is inevitable that a small number of microstructures (< 20%) are failed to be bent. (3) We have further strengthened the manuscript by showing that this strategy can be applied to other organic crystal systems, each yielding a characteristic of bend angles. This tunability is precisely what makes the approach promising for applications like integrated photonic circuits, where having a portfolio of components with different bending geometries is essential for flexible spatial layout.\nFigure R1. Randomly selecting the area to characterize the distribution of the bent crystalon the substrate. FM images of bent crystals in the area 1 (A), area 2 (B), area 3 (C), area 4 (D), area 5 (E), area 6 (F))..\nRevision: We have added the discussion around the scale-up preparation and repeatability of bent crystals. On page 6) l`] k]fl]f[]k  To ensure our analysis is representative and reproducible, we randomly selected areas from several independently prepared samples, as shown in Figure R1, a large number of bent microstructures with the angle of 146(cid:127)148° are distributed in different areas of kmZkljYl]+‚ `Yn] Z]]f Y\\]\\ af l`] j]nak]\\ eYfmk[jahl+ Figure R1 has been added in the revised supplemental information as Supplementary Fig. 8.\nP`] \\YlY YnYadYZadalq klYl]e]fl af\\a[Ylaf_ l`Yl \\YlY Yj] YnYadYZd] ^jge l`] Yml`gjk gf j]im]kl ak ]plj]e]dq \\akYhhgaflaf_+ E ogmd\\ kljgf_dq ]f[gmjY_] l`] Yml`gjk lg ]fkmj] l`Yl l`] \\YlY Yj] YnYadYZd] oal` hmZda[Ylagf af kmhhgjl g^ gh]f k[a]f[]) ]kh][aYddq a^ l`]q Yae lg hmZdak` af Y `a_` aehY[l bgmjfYd o`]j] j]kmdlk k`gmd\\ Z] gh]f lg k[jmlafq+ P`ak ak hYjla[mdYjdq ljm] _an]f l`] dgo d]n]d g^ \\YlY hj]k]fl]\\ af l`] AOE Yf\\ eYaf eYfmk[jahl) ]kh][aYddq Yjgmf\\ l`] kaemdYlagfk) o`]j] fg af^gjeYlagf ak Y[lmYddq YnYadYZd] gf l`]aj gmlhmlk+\nResponse: We sincerely appreciate the reviewer„s feedback regarding data availability and fully agree with the importance of open science. We apologize for the inadequate data availability statement in the initial submission. To fully support open access and data scrutiny, we will deposit all relevant raw data, including experimental datasets and simulation outputs upon acceptance, and provide the corresponding access links in the final manuscript. The dataset will include crystallographic files, simulation results, raw PXRD patterns, and any additional data necessary to support the findings presented in this study.\nEf Y\\alagf lg l`]k] ZjgY\\]j [jala[akek) E ogmd\\ dac] l`] Yml`gjk lg kljgf_dq [gfka\\]j Y fmeZ]j g^ Y\\alagfYd hgaflk) o`a[` E kmeeYja]k`]j] af gj\\]j g^ j]Y\\af_7\nDetailed point-bbyy-point responses:\n..++ Ef l`] afljg\\m[lagf 'h/( l`] Yml`gjk ojal] YZgml Y ƒkhgflYf]gmk ljYfkalagf ^jge kdahhY_] lg Z]f\\af_„+ =l l`ak hgafl g^ l`] eYfmk[jahl) al ak fgl [d]Yj o`Yl l`ak e]Yfk+\nResponse: Thanks for this worth comment. In the introduction, the phrase “spontaneous transition from slippage to bending” refers to a unique process observed in our system, where the crystal undergoes bending spontaneously without the need for external mechanical force.\nSpecifically, unlike previous studies where crystal bending was induced by external stimuli and resulted in a continuous curvature (without well-defined bending angles, Figure 2A), our method involves a thermally induced slipping of molecular layers, followed by an increase in solute concentration, which triggers a spontaneous transition from slipping to bending. This process produces crystals with well-defined bendingangles (Figure 2B), as opposed to a gradual curvature.\nFigure R2. Schematics representing molecular arrangements in a conventional bent structure (A) and in the structure proposed in this work (B))..\nMore importantly, in conventional bending (Figure R3a-ii)), the non-uniform curvature leads to molecular strain, i.e., compression in regions of smaller curvature and stretching in regions of larger curvature, resulting in heterogeneous crystallinity (Figure R3j). In contrast, our slipping-ttoo-bending transition occurs in a coordinated manner that avoids stretching or compressing molecules at the bending interface, thereby preserving uniform crystallinity throughout the crystal.\n[REDACTED]\nFigure R3. ((aa-ii)) Elastic bending under mechanical stress applied through a pair of tweezers. (j) Graphical presentation of the packing-structure variation when the crystal is bent to form a half loop(Angew. Chem. Int. Ed. 2018, 5577, 8448).\nRevision: We have clarified this point in the revised manuscript to avoid confusion. On page 3, t`] k]fl]f[]  The present work addresses this issue by employing a directional noncovalent interaction strategy toward the self-assembled molecular crystals to induce a spontaneous deformation transition from slippage to bending without destroying the crystal integrity.‚ `Yk Z]]f j]nak]\\ Yk  In this study, we demonstrate the spontaneous bending of organic crystals with well-defined bending angles, without applying external mechanical force. This behavior is achieved through a cocrystal engineering strategy that introduces directionally distinct noncovalent interactions. As illustrated in Figure 1B, a system based on a single polycyclic aromatic hydrocarbon molecule with isotropic intermolecular interactions (where E1 } E2 ) Original Original\ntends to self-assemble into 1D or 2D micro/nanostructures along the directions governed by these interactions. The introduction of electron-withdrawing cyanide groups breaks this isotropy, creating anisotropic interactions (i.e., E > E ). In New Original\nthe newly formed cocrystals, the non-covalent intermolecular interactions along the orthogonal direction are weakened due to the high temperature of the substrate, which oYk eYaflYaf]\\ Yl 0-(cid:157)y? mkaf_ Y l]eh]jYlmj] [gfljgdd]j+ P`ak l`]jeYd ]^^][l af\\m[]k Y slip deformation within the crystal structure.‚\n/+ Ef l`] afljg\\m[lagf l`] Yml`gjk \\ak[mkk Y kljYl]_q lgoYj\\k k]d^*Ykk]eZd]\\ [jqklYdk lg af\\m[] khgflYf]gmk ljYfkalagf ^jge kdahhY_] lg Z]f\\af_ oal`gml \\]kljgqaf_ l`] [jqklYd afl]_jalq+Elakfgl[d]Yjo`Yll`ake]Yfk)gjo`YlakZ]af_[jala[ar]\\`]j]+P`]j]Yj]eYfq e][`Yfa[Yddq ^d]paZd]) hdYkla[) ]l[+ [jqklYdk l`Yl Z]f\\ oal`gml Y^^][laf_ l`] gn]jYdd afl]_jalq g^ l`] [jqklYd) Yf\\ o`a[` \\g fgl Y^^][l l`] ghla[Yd oYn] _ma\\af_ fYlmj] g^ l`] [jqklYdk+\nResponse: Thank you for this important question. In our work, the strategy focuses on modulating non-covalent interactions in the crystal to enable a spontaneous bending transition with well-defined angles, while preserving uniform molecular alignment at the interface. By contrast, many previously reported mechanically flexible or plastic crystals are curved through the application of external force, resulting in elastic or plastic deformation characterized by continuous curvature rather than sharp, well-defined bending angles. In such curved crystals, molecular packing is inevitably compressed on the inner side of the curve and stretched on the outer side. Since light propagates perpendicular to the direction of transition dipole moment, which is determined by molecular alignment, any non-uniformity in molecular packing, such as compression or stretching, can influence optical propagation. Our approach aims to achieve bending without introducing such molecular-scale distortion, thereby maintaining both structural and optical homogeneity throughout the bent region.\n0+P`]Yml`gjkojal] mhgfYkmZkljYl]oal`Yj]dYlan]dq`a_`l]eh]jYlmj]g^0-õ)„„Zml al ak fgl[d]Yjo`Yl l`]e]Yfaf_ak+\nResponse: Thanks for this worth comment.We agreed that the description of relatively high temperature was unclear and modified it in the revised manuscript. As shown in Figure R4, the temperature of substrate in our experiment was precisely controlled and maintained using an electric temperature controller to ensure a consistent temperature.\nFigure R4. The temperature controller used to control the temperature of substrate.\nRevision: On page 3, the sentence (cid:129)In the newly formed cocrystals, the original weak orthogonal noncovalent intermolecular interactions tend to be weakened upon a kmZkljYl] oal` Y j]dYlan]dq `a_` l]eh]jYlmj] g^ 0- õ) j]kmdlaf_ af l`] kdahhY_] g^ l`] crystals.‚ `Yk Z]]f j]nak]\\ Yk  In the newly formed cocrystals, the non-covalent intermolecular interactions along the orthogonal direction are weakened due to the high l]eh]jYlmj] g^ l`] kmZkljYl]) o`a[` oYk eYaflYaf]\\ Yl 0-(cid:157)y? mkaf_ Y l]eh]jYlmj] controller. This thermal effect induces a slip deformation within the crystal structure.‚\n1+ El ak fgl [d]Yj o`Yl e][`Yfake l`] Yml`gjk Yj] hjghgkaf_ o`]f l`]q ojal]7 ƒ„P`] [gflafmgmk _jgol` g^ l`] Ykk]eZd]\\ egd][md]k Yl Zgl` ]f\\k g^ l`] kdahhY_] ea[jgkljm[lmj] [Ymk]k l`] klj]kk gf l`] kdahhaf_ kmj^Y[] lg af[j]Yk] [gflafmgmkdq) mdlaeYl]dq d]Y\\af_ lg khgflYf]gmk jglYlagf Yk Y e]Yfk g^ klj]kk j]da]^„„ gj o`]f l`]q hjghgk] ƒ„ hjghgk]\\ af l`ak ogjc mf\\]j_g]k Y [gfljgdd]\\ Z]f\\af_ Yl Y kh][a^a[ Yf_d] l`jgm_` Y jglYlagf hjg[]kk) eYaflYafaf_ alk gja_afYd egd][mdYj YjjYf_]e]fl oal`gml mf\\]j_gaf_ klj]l[`af_ gj [gehj]kkan] \\]^gjeYlagf 'Yk addmkljYl]\\ gf l`] ja_`l ka\\] g^ Ba_mj] .=„„+ E l`afc al ak yjla[mdYjdq \\a^^a[mdl lg mf\\]jklYf\\ o`Yl ak Z]af_ hjghgk]\\ Yk l`] eg\\]d l`] Yml`gjk k]]e lg Z] [gfljYklaf_ af Ba_mj] .= ak Yf gd\\ 'Yf\\ gml*\\Yl]\\( eg\\]d l`Yl ak hjghgk]\\ ^gj e][`Yfa[Yd Z]f\\af_ g^ [jqklYdk) Zml l`] hj]k]fl eYfmk[jahl \\ak[mkk]k _jgol` g^ Z]fl [jqklYdk8 fgl hgkl*_jgol` Z]f\\af_+ P`ak ak Y [gf^mkaf_ [gehYjakgf\nResponse: Thank you for this insightful comment. You have correctly identified a point of confusion in our original manuscript, for which we apologize. The comparison in Figure 1A was intended not to contrast the mechanism (self-assembly growth vs. mechanical bending) but to illustrate the fundamental difference in the outcome at the molecular scale: uniform molecular alignment in our spontaneously bent crystals versus the distorted alignment (compression/stretching) typically found in mechanically curved crystals. We have revised the text and figure caption to clarify that the (cid:129)Mechanical Bending‚ model serves as a widely recognized reference to highlight the molecular-level integrity achieved in our approach.\nRegarding the proposed mechanism for spontaneous bending during growth, please allow us to clarify. The molecular packing in our crystals features anisotropic non-covalent interactions (Figure R5A and B), namely, strong charge-transfer afl]jY[lagfk Ydgf_ l`] dgf_ Ypak Yf\\ o]Yc]j •-• afl]jY[lagfk af Y f]Yjdq h]jh]f\\a[mdYj direction. The process can be broken down as follows:\n((11) Slip Initiation: When the solution is drop-cast onto a high-temperature substrate '0-y?() l`] l]eh]jYlmj] o]Yc]fk l`] o]Yc]j •-• afl]jY[lagfk+ P`ak Yfakgljghq af interaction strength enables the crystal to undergo a slippage along the crystal plane with the weakest interfacial bonding force (Figure R5C), leading to the initial misalignment of the primary crystal (Figure R5D).\nFigure R5. (A) Schematic diagram of the intermolecular interactions within the cocrystal 8&11. (B) TEM image of cocrystal 8&11. (C) Schematic diagram showing the (001) crystal plane slip caused by the disruption of intermolecular interactions in the cocrystal 8&11. (D) TEM image of slipped cocrystal 8&11.\n(2) Stress Accumulation: The two slip surfaces of the microstructure are typically not identical in area. We utilized concave substrates to control solute transport asymmetrically. As illustrated in Figure R6A and B, the higher solution concentration at the bottom of the concave substrate promotes faster growth on that side, leading to asymmetric crystal growth (Figure R6C and D) and the build-up of interfacial stress. This inference was verified using substrates with different curvatures. This asymmetry creates an interfacial stress. Crucially, solute molecules continue to deposit and the crystal grows at both ends during this stage. This continuous growth on an already misaligned and asymmetric structure acts as a process that progressively increases the interfacial stress.\nFigure R6. (A) Schematics of the concave substrates with different curvatures employed in the experiment. (B) Schematic of the solute distribution on the concave bottom surface. (C, D) TEM images of bent crystals grown under substrates with curvatures of (C( 2- eð  Yf\\ 'D( 33+4 eð ) j]kh][lan]dq+ 'E) The relationship between the substrate curvature and the probability of crystal bending.\n(3) Stress Relief via Rotation:When the accumulated interfacial stress reaches a critical threshold, the system relieves this energy through a spontaneous rotation of the slipped segments) o`]j] =f_d] . : =f_d] .„) =f_d] / : =f_d] /„ 'Ba_mj] N4(. This rotation occurs along the pre-existing slip plane, effectively locking the structure into a new, stable configuration with a well-defined bendingangle.\nFigure R77.. TEM micrograph of (A) slipped and (B) bent structure.\n(4) Preservation of Molecular Order: Because the bending is achieved by a rotation of rigid blocks rather than the continuous deformation of the lattice, the original molecular arrangement within each block is preserved without experiencing the compressive or tensile distortions inherent to mechanical bending. This is key to maintaining uniform optical properties.\nIn summary, our strategy utilizes the anisotropy of non-covalent interactions, tuned by temperature (inducing slip) and concentration (driving growth under stress), to achieve a spontaneous bending with a defined angle. This represents a distinct mechanism compared to the post-growth application of external mechanical force.\n2+ P`] Yml`gjk `Yn] km__]kl]\\ l`Yl (cid:129)P`] \\]lYad]\\ ]ph]jae]flYd hjg[]\\mj]k Ydgf_ oal` l`] j]kmdlYfl [jqklYd kljm[lmj]k Yj] hj]k]fl]\\ af Omhhd]e]flYjq IYl]jaYdk„„ Dgo]n]j fg km[` \\]lYadk Yj] Y[lmYddq _an]f+\nResponse: S] kaf[]j]dq Yhhj][aYl] l`] j]na]o]j„k [Yj]^md j]Y\\af_ g^ gmj eYfmk[jahl and for raising this point. In the revised version, the full experimental details have been included in the Supplementary Information file. This includes:\n(11)) Materials\nDichloromethane (DCM, analysis grade), methanol (MeOH, analysis grade), ethanol (EtOH, analysis grade) was purchased from Beijing Chemical Agent Ltd., China. The compounds of 1-Methylpyrene (1, CAS: 2381-2211-7), pyrene (2, CAS: 129-0000-0), anthracene (4, CAS: 120-1122-7), carbazole (5, CAS: 86-7744-8), phenanthrene (6, CAS: 8855-0011-8), perylene (8, CAS: 198-5555-0), acridine (9, CAS: 260-9944-6), benzene-1,2,4,5-tetracarbonitrile (12, CAS: 712-7744-3), were purchased from Sigma-Aldrich. 2,7-ddii-tert-butylpyrene (3, CAS: 24300-91-2), pyrene-4,5,9,10-tetraone (10, CAS: 14727-71-0), 3,4,5,6-Tetrachlorobenzene-1,2-dicarbonitrile (13, CAS: 1953-99-7), were purchased from TCI. 4H-Dithieno[3,2-b:2',3'-d]pyrrole (7, CAS: 88537-32-0), 2,4,6-trimethylbenzene-1,3,5-tricarbonitrile (11, CAS: 1206-85-5), were purchased from Adamas. In addition, all solvents and compounds were used without further treatment.\n(2) Preparation of large crystals\nThe TBT-Perylene large cocrystals employed for structural analysis were prepared via the liquid(cid:127)liquid diffusion method.1 Typically, 0.1 mmol of TBT and 0.1 mmol of perylene were dissolved in 10 mL of dichloromethane (DCM) in a sample vial at room l]eh]jYlmj])qa]d\\af_Y[gf[]fljYlagfg^.-+-eegdˆHð +P`]f)/-eHg^]l`Yfgd'AlKD( was carefully layered on top of the DCM solution to establish a clear liquid(cid:127)liquid interface. The mixture was allowed to stand undisturbed for three days to facilitate slow solvent evaporation. Subsequently, bulk TBT-Perylene cocrystals were obtained.\n(3) Synthesis of the organic slipped microcrystals\nAcceptor and donor molecules in a 1:1 molar ratio were dissolved in 10 mL of DCM to gZlYafYkgdmlagfoal`Y[gf[]fljYlagfg^/eegdHð(cid:143)+P`]f).-eHg^l`akklg[ckgdmlagf was introduced into 10 mL of EtOH. The resulting mixture was drop-cast onto quartz substrates that maintained at temperatures of 30, 32 °C, respectively. After complete solvent evaporation, microstructures identified as 1-slip, 2-slip were observed on the respective substrates, respectively.\n(4) Synthesis of the organic bent microcrystals\nAcceptor and donor molecules in a 1:1 molar ratio were dissolved in 10 mL of DCM to gZlYafYkgdmlagfoal`Y[gf[]fljYlagfg^2eegdHð(cid:143)+P`]f).-eHg^l`akklg[ckgdmlagf was introduced into 10 mL of EtOH. The resulting mixture was drop-cast onto quartz substrates that maintained at temperatures of 30, 32, 34, 36, 38, and 40 °C, respectively. After complete solvent evaporation, microstructures identified as 1-bend, 2-bend, 3-bend, 4-bend, 5-bend and 6-bend were observed on the respective substrates, respectively.\n(5) Structure characterizations\nThe SEM images of the samples were obtained by a FESEM, Carl Zeiss, Supra 55 at acceleration voltages of 20 kV. The TEM images were observed by a transmission electron microscopy (FEI company, Tecnai G2 F20, United States). The solution was dropped on a carbon coated copper grid and evaporated. TEM measurement was performed at an accelerating voltage of 120 kV at room temperature. FM images were measured by a fluorescence optical microscope (Leica, DM4000M, Germany) with a spot-enhanced charge couple device (Diagnostic Instrument, Inc). The excitation source is a mercury lamp equipped with a band-pass filter (330-380 nm for UV-light). Single crystal data were obtained by the single crystal X-ray Diffraction (SCXRD) analysis. X-ray diffractions was carried out at 170 (2) K on a Bruker D8 VENTURE diffractometer using Mo-G‘ jY\\aYlagf 'J = 0.71073 Å). Integration and scaling of intensity data were performed using the SAINT program. Data were corrected for the effects of absorption using SADABS. The structures were solved by direct method and refined with full-matrix least-squares technique using SHELX-2014 software. Non-hydrogen atoms were refined with anisotropic displacement parameters, and hydrogen atoms were placed in calculated positions and refined with a riding model. The molecular structure and configuration are analyzed by importing the corresponding cif file into the Mercury software. The simulated growth morphology and crystal facet parameter are conducted based on single-crystal data by the Materials Studio software package. The XRD patterns were measured through a D/max 2400 X-ray diffractometer oal` ?m G‘ jY\\aYlagf 'J : .+21-2- v( gh]jYl]\\ af l`] /“ jYf_] ^jge 2y lg 1-y+ PC= was performed on TA SDT 2960 instrument. The samples were placed in a platinum crucible and heated at a rate of 10 °C/min from room temperature to 500 °C under flowing nitrogen, the temperature at 5% weight loss was regarded as the decomposition temperature. DSC was performed on a TA DSC 2010 during the heating and cooling runs from room temperature to 250 °C with a heating rate of 10 °C/min under nitrogen.\n(6) Optical characterizations\nMicro-area photoluminescence (K-PL) spectra were collected by a homemade optical microscopy. In order to get the optical-loss coefficient, we measured the PL spectra of individual microrod. The microrod was excited locally with a 380 nm laser focused down to the diffraction limit. The excitation laser was filtered with a 380 nm notch filter. The light in microrod guided to the end subsequently and recorded by a thermal-electrically cooled CCD (Princeton Instruments, PIX-256E). PL microscopy images were taken with an inverted microscope (Olympus, BX43).\nRevision: We have added the corresponding materials and detailed experimental procedures on the page S2-S5 in the revised supplemental information. The corresponding references have been added on the page 59 in the revised supplemental information.\n3+ Ef Ba_mj] O0) l`] hj]\\a[l]\\ egjh`gdg_a]k Yj] YZkgdml]dq fgl [gfkakl]fl oal` l`] egjh`gdg_a]k gZk]jn]\\ Zq ea[jgk[ghq+ P`] kaemdYl]\\ egjh`gdg_a]k Yj] Zdg[c*dac]) o`adkl l`gk] gZk]jn]\\ ]ph]jae]flYddq Yj] jg\\k+ El ak Ydkg fgl [d]Yj o`Yl l`] 0 \\a^^jY[l ^a_mj]k afO0j]^]j lg+P`]kYe]`gd\\k ^gjYdd dYl]jegjh`gdg_qhj]\\a[lagfk Yk o]dd+\nResponse: Thank you for this critical comment, which allows us to clarify an important aspect of our morphology analysis and improve the presentation of our data.\n(1) Regarding the inconsistency between simulated and experimental morphologies: We agree with your observation that our initial simulated morphologies (block-like) differed from the experimental ones (rod-like). This discrepancy arises from a fundamental difference in the growth conditions between the two situations. The large single crystals employed for structural analysis were grown via slow evaporation Yl jgge l]eh]jYlmj] 'u/- õ() Y [gf\\alagf l`Yl Yddgok l`] kqkl]e lg YhhjgY[` thermodynamic equilibrium and results in their characteristic block-like habit. In contrast, the micro crystals in our functional experiments were formed at elevated l]eh]jYlmj]k 'u0- õ( oal` Y ^Ykl]j _jgol` jYl]. Under these kinetic conditions, molecules are self-assembled more rapidly into faces with higher attachment energy (the tip facets, Figure R8 and Table R1), while the slower-growing lateral facets with lower attachment energy do not have sufficient time to develop. This kinetic-driven process results in the rod-like morphology.\nFigure R8. The simulated growth morphology of cocrystal 8&11.\nTable R1. The simulated parameters of the growth morphology of cocrystal 8&11.\nhkl dhkl (Å) E (kcal mol-1) Total facet area (%)\natt\n{001} 11.30 -44.37 19.78\n{010} 9.74 -47.64 15.23\n{101} 8.72 -35.06 25.72\n{110} 8.06 -38.01 21.99\n{111} 7.67 -60.27 0.68\n{01-1} 7.53 -46.73 6.08\n{011} 7.24 -60.85 1.87\n(2) Regarding the unclear presentation of the three morphologies: We sincerely apologize for the lack of clarity in the original figure. The three panels originally represented three common computational approaches for predicting crystal morphology: Growth Morphology, Equilibrium Morphology, and Bravais-Friedel-Donnay-Harker (BFDH) Morphology. These three panels utilize the same initial data (the crystal cell parameters and space group), to predict the ideal macroscopic morphology of the crystal. Each model outputs a set of major exposed crystal planes along with their relative size proportions, which collectively form a predictive crystal morphology model. Despite sharing a common input, the three approaches are founded on distinct physical principles. The Growth Morphology model operates on kinetic principles by calculating l`] YllY[`e]fl ]f]j_q 'Ažôô(^gj]Y[`[jqklYd hdYf]+= egj] f]_Ylan]YllY[`e]fl ]f]j_q (i.e., a larger absolute value) corresponds to a faster growth rate along that direction, causing such facets to diminish or disappear. As a result, the ultimate morphology is dominated by the slowest-growing planes. In contrast, the Equilibrium Morphology model is derived from thermodynamics. It computes the surface energy of each facet, where a lower surface energy indicates greater stability and leads to a larger exposed area. The model aims to find the configuration that minimizes the total surface energy, reflecting the morphology under thermodynamic equilibrium. The BFDH model, based purely on geometric considerations, associates larger interplanar spacing (dñòó) with higher surface density of lattice points. Such dense planes exhibit slower growth rates and are therefore more likely to remain prominently exposed in the final crystal habit.\nAlthough these three models are based on completely different physical assumptions, the main crystal faces they predict are highly consistent. This, from multiple perspectives, jointly proves the reliability of our crystal structure analysis. However, we fully acknowledge that presenting all three could be confusing for the reader. Following your feedback, we have simplified this presentation in the revised manuscript. We now present only the Growth Morphology simulation, which is the most relevant for direct comparison with our experimentally observed kinetics-controlled growth. This simplified presentation focuses the discussion and provides a clearer, more direct correlation with our XRD and dihedral angle analysis.\nRevision: We have updated Figures to focus solely on the simulated growth morphology. Additionally, we have combined X-ray diffraction and dihedral angle measurements to conduct a systematic analysis of the slip angle and bending angle. We believe these revisions provide a more coherent explanation for the crystal growth mechanism.\n4+EfBa_mj]O2alakfgl[d]Yjo`Yl^]Ylmj]l`]Yml`gjkYj]j]^]jjaf_lgYkZ]af_af\\a[Ylan] g^kdah+P`]kYe]k`Y\\goaf_akk]]fafl`]ƒfgf*Z]fl„[jqklYdafO2+=kaeadYj[gf^mkagf ak Yjgmf\\Ba_mj] O..Yf\\l`] afk]lk+\nResponse: We sincerely thank the reviewer for this insightful comment, which offers us an opportunity to further clarify the evidence for slip planes in our samples. The characteristic feature indicating the slip of crystal is the presence of a distinct line or interface observable across various microscopy techniques. Since crystal slip is an atomic-scale process that occurs along specific crystallographic planes, it is often difficult to resolve clearly. Under fluorescence microscopy (FM) and scanning electron microscopy (SEM), the evidence typically appears as a faint slip line or a subtle contrast change (Figure R9 and R1100)).. Furthermore, transmission electron microscopy (TEM) allows the same feature to be clearly resolved as a sharp and well-defined interface between two distinct crystal domains (Figure R1111), exhibiting a clear difference compared to the unslipped crystal structure (Figure R1122)).. The bent crystal structures we propose are generated via slip-mediated mechanisms. Consequently, the slip interface can be observed in both the slip (unbent) structures and the resulting bent crystals.\nFigure R9.FM image of the slipped crystal with slip line.\nFigure R1100.SSEEM image of the slipped crystal with slip line.\nFigure R1111.TTEEM image of the slipped crystal with distinct slip line.\nFigure R1122.TTEEM image of the straight 1D crystal without slip line.\nRevision: To make the slip featuresof crystal clearer, we have now explicitly marked the slip lines with dashed lines in the revised versions of Figure S5 and Figure S11. We believe these additions will help readers better identify the key structures indicative of slip. The revised figures are included in the updated supplementary information.\n5+ Ra\\]g O. []jlYafdq k`gok l`Yl l`] [jqklYd Z]f\\k \\mjaf_ ]nYhgjYlagf g^ kgdn]fl) Zml al ak fgl [d]Yj `go l`] na\\]g km__]klk ]na\\]f[] g^ Y kdah*Z]f\\ e][`Yfake+\nResponse: Thank you for this important comment. We agree that the bending phenomenon alone is not direct proof of the mechanism, and we appreciate the opportunity to clarify how the video evidence is interpreted in the context of our multi-faceted analysis. Our conclusion regarding the slip-bend mechanism is not based on the video alone, but on the correlation between the dynamic process in the video and the quantitative structural data from TEM. The growth video as well as the corresponding fluorescence microscope images obtained simultaneously provides ccrritical temporal context by showing that the development of slip lines precedes the bending event(Figure R13), and that the crystal then undergoes a continuous, gradual rotation along these lines to form the final bent morphology. This sequence is crucial as it demonstrates the slip-mediated process dynamically.\nFurthermore, this observed process is strongly substantiated by TEM analysis (Figure R14), which confirms that the angles within the slip crystal are consistent with the bent crystal. Therefore, Video S1 serves as the real-time record of the mechanism in action, while TEM provides the quantitative structural proof, and together they form a cohesive line of evidence for the slip-bend mechanism.\nFigure RR113. FM images of (A) slipped crystals and (B) bent crystals captured during the crystal growth process.\nFigureR1144. TTEEM images of (A) slipped crystal and (B) bent crystal.\n6+ Ef O3 l`] Yml`gjk Yj] [gehYjaf_ jYlagk Ydh`Y . Yf\\ Ydh`Y /+ P`]k] e]Ykmj]e]flk Yj] \\gf] eYfmYddq gf Y PAI ^a_mj]) Zml l`]j] ak fg af\\a[Ylagf g^ l`] Y[[mjY[q gj j]hjg\\m[aZadalq g^ l`]k] e]Ykmj]e]flk) gj Ykkg[aYl]\\ ]jjgjk+ El ak \\a^^a[mdl lg Z] [gfnaf[]\\ l`Yl l`] n]jq keYdd g^^k]l ak j]Yd) jYl`]j l`Yf Yf YZ]jjYlagf) kdah g^ l`] `Yf\\ \\mjaf_ e]Ykmjaf_) gj ]n]f \\m] lg kge] keYdd [jqklYd ^jY_e]fl Y__dge]jYlaf_ lg l`] ka\\] g^ l`] dYj_]j [jqklYd+\nResponse: We thank the reviewer for this critical comment regarding the reliability of gmj e]Ykmj]e]flk+ S] Y_j]] l`Yl \\]egfkljYlaf_ l`] jgZmklf]kk g^ l`] ‘ ,,‘‘ ratio 1 2 measurements is essential. Since it is challenging to capture intermediate states (slip crystal)of bent crystal duringTEM observation, we have supplemented our study with additional TEM images of the final bent crystals (Figure R15c and d)).. These images consistently show a clear width disparity across the bending interface, which we attribute to the use of a concave glass substrate during growth. Since we deduced that the crystal„s transition from a slip state to a bend state is driven by the release of interfacial stress, which originates from a difference in the surface area of the growth interfaces. To test this, we utilized concave substrates to control solute transport asymmetrically. As illustrated in Figure R1b, the higher solution concentration at the bottom of the concave substrate promotes faster growth on that side, leading to asymmetric crystal growth and the build-up of interfacial stress. This inference was verified using substrates with different curvatures (Figure 15a). The results show a clear trend: a greater substrate curvature leads to a higher degree of crystal asymmetry and a correspondingly increased probability of bending (Figure R15ee)). Although manual measurements were used, the observed width differences and angular offsets are reproducible across multiple crystals and are supported by this physical explanation.\nWe are confident that the small offset reflects a real phenomenon related to stress-driven bending rather than measurement error or artifacts.\nFigure R15. (A) Schematics of the concave substrates with different curvatures employed in the experiment. (B) Schematic of the solute distribution on the concave bottom surface. (C, D) TEM images of bent crystals grown under substrates with curvatures of (C( 2- eð  Yf\\ 'D( 33+4 eð ) j]kh][lan]dq+ 'E) The relationship between the substrate curvature and the probability of crystal bending.\nRevision:We have added a detailed explanation in the manuscript regarding the origin of the width disparity that attributed to asymmetric solute deposition resulting from the concave substrate on Page 6 in the revised manuscript.\n.-+ P`jgm_`gml l`] eYfmk[jahl) l`]j] ak fg \\ak[mkkagf Yjgmf\\ o`]l`]j l`] ƒZ]fl„ [jqklYdk Yj] af ^Y[l Y kaf_d] [jqklYd) gj a^ l`]q j]kmdl ^jge Y__dge]jYlagf g^ log [jqklYdk l`jgm_` Y \\akgj\\]j]\\ afl]j^Y[]+ S`Yl ]na\\]f[] \\g l`] Yml`gjk `Yn] ^gj l`] Z]fl [jqklYdk Z]af_ Y kaf_d] [jqklYd<\nResponse: Thank you for raising this important point. Based on our in-situ growth observations (Video R1), the bent structure evolves continuously from an initially straight and single 1D slip crystal. Throughout the growth process and solvent evaporation, this single crystalline structure gradually and spontaneously bends without fracture. Therefore, we believe that the bent architecture forms from a single crystalline entity rather than through the traditional mechanism of epitaxial growth outward from a disordered interface.\nVideo R1. The bending process of the organic 1D microcrystal recorded by a bright-field microscope.\nRevision: We have added the discussion around whether the bent crystals are a single [jqklYd+KfhY_]1)l`]k]fl]f[]k(cid:129)@mjaf_l`]k]d^-assembly bending process, the crystal is induced into a slipped state before 1.09 s, subsequently undergoing bending through a rotation to an angle of approximately 155° at 1.11 s, after which the bending angle gradually decreases to approximately 148° at 2.06 s. This continuous bending process demonstrates that the crystal is a single entity, thereby excluding the possibility of ]halYpaYd _jgol` Z]lo]]f log k]hYjYl] [jqklYdk+‚ have been added in the revised manuscript.\n..+EfBa_mj]O..alakfgl[d]Yja^l`]hj]*Yf\\hgkl*Z]fl[jqklYdkYj]l`]kYe][jqklYd+E^ fgl)`gomk]^md ak l`] [gehYjakgf<\nResponse: Thank you for raising this point. The SEM images in Figure R16 do not depict the exact same crystal before and after bending. This is due to a fundamental technical constraint: the slipping to bending process of the crystals occurs during solvent evaporation, and real-time capture of this dynamic process within the SEM is exceptionally challenging. The solvent evaporation would interferes with the instrument’s electron optics, preventing stable imaging.\nTherefore, we employed a complementary two-technique approach to conclusively demonstrate the phenomenon. First, the bending process was successfully captured in real-time for the same single crystal using optical microscopy, as shown in Figure R16. This sequence provides direct, sequential evidence that the crystal angle of pre-and post-bent crystals.\nSecond, the role of the SEM images in Figure R1177 is to provide high-resolution morphological characterization of the crystal states. The pre- and post-bent SEM images, while from different crystals, are representative of the structural states before and after the bending procedure. Specifically, the high-resolution SEM images allow us to clearly observe the slip lines on the crystal surface, which are the key microstructural features associated with the deformation mechanism. This detailed morphological analysis is the primary value of the SEM data. The high agreement between the bending angles measured by optical microscopy on the same crystal and those observed in the representative SEM images validates the comparison. Thus, the utility of Figure R1177 lies in demonstrating that the bending process results in a well-defined structure without catastrophic fracture, complementing the dynamic proof provided by optical microscopy.\nFigure R16. Optical images of the typical (A) slipped and (B) bent cocrystal 2&11, which shows the rotation process with the angle of 180°.\nFigure R1177. (A) The SEM micrograph of the slipped cocrystal 2&11, inset shows the magnified SEM image displaying the slipped interface. (B) The SEM micrograph of the bent cocrystal 2&11 with sharp boundary between the domains. Inset: the magnified SEM image displaying the bent interface.\nRevision:P`] k]fl]f[]  P`] ghla[Yd aeY_]k g^ [g[jqklYd 2&11 before and after bending further demonstrate how the rotation and bending of the slipped crystals release interfacial strain (Figure R16)).. Figure R16has been added in the revised supplemental information as Supplementary Fig. 9.\n./+ E Ye imal] [gf^mk]\\ YZgml l`] [gehYjakgf g^ ƒkaemdYl]\\„ Yf\\ ]ph]jae]flYd LTN@ hYll]jfk af l`] AOE ^gj l`] jYf_] g^ [g[jqklYdk+ Bajkl) al ak fgl [d]Yj o`]j] l`] ]ph]jae]flYd gj kaemdYl]\\ \\YlY [Ye] ^jge+ O][gf\\) al ak imal] [gf[]jfaf_ l`Yl ^gj Ydegkl fgf] g^ l`] [jqklYdk \\g l`] ]ph]jae]flYd Yf\\ kaemdYl]\\ \\YlY eYl[`+ P`ak km__]klk Y hgl]flaYddq ka_fa^a[Yfl ]jjgj af l`] \\YlY) gj h]j`Yhk l`Yl hgo\\]j \\a^^jY[lagf oYk ee]]Ykmj]\\ gf kaf_d] [jqklYdk 'Zml o`q<() o`a[` j]kmdlk af eYbgj l]plmjaf_+ P`ak f]]\\k lg Z] ]phdYaf]\\+\nResponse: Thank you for these important questions regarding the PXRD patterns. We appreciate the opportunity to clarify. (1) Source of the data: The simulated PXRD patterns were generated from the single-crystal diffraction data (CIF files) of each respective cocrystal structure. The experimental PXRD patterns were collected from microcrystalline powder samples of the same batch used for single-crystal formation. We apologize for not clearly labeling the origin of each dataset in the ESI and will revise the figure captions accordingly to avoid confusion. (2) Mismatch between simulated and experimental patterns: We did not perform PXRD measurements on single crystals, all experimental data were obtained from powdered samples. However, we identified that the observed peak shift was primarily caused by excessive thickness of the powder sample during the measurement, which created an uneven surface and introduced a displacement error relative to the ideal focal plane.This imperfection in sample preparation resulted in a systematic shift in the diffraction peaks. We have since reperformed the PXRD measurements with a properly prepared thin and even layer of powder. The new experimental patterns now align well with the simulated ones.\nFurthermore, in response to this issue, we have reorganized the structural presentation of our manuscript to strengthen the logical flow and clarity. For instance, based on the proposed bending mechanism€which occurs along the crystal plane with the largest interlayer spacing, i.e., the plane with the weakest interlayer interactions€ we first simulated the growth morphology of the 8&13 cocrystal (Figure R18A). This allowed us to identify the (002) plane as the one with the largest interlayer spacing (Table R2). Combining the simulated growth morphology with XRD data, we further [gf^aje]\\ l`Yl l`] [jqklYd„k lgh kurface corresponds to the (011) plane (Figure R18B). The theoretical dihedral angle between the (002) and (011) planes was calculated to be 61.3°(Figure R18C), which is in close agreement with the actual bending angle of 61.8° observed in the crystal. We extended this analysis to other cocrystals (Figure R19 and R20), determining the dihedral angles between their respective largest-interlayer-spacing planes and their top/sidesurfaces (which have comparable surface areas). In all cases, the calculated angles consistently matched the experimentally observed bending angles. These results strongly support the inference that bending occurs preferentially along the crystal plane with the largest interlayer spacing.\nFigure R18. (a) The simulated growth morphology of cocrystal 8&&113 based on the attachment energy. (b) The XRD pattern of cocrystal 8&&113 (top) and simulated XRD pattern (bottom). (c) Schematics illustrations of the spatial relationships between the bending and top/side crystal planes.\nTable R22..The simulated parameters of the growth morphology of cocrystal 8&13.\nhkl d (Å) E (kcal mol-1) Total facet area (%)\nhkl att\n{002} 8.10 -161.91 25.54\n{011} 7.79 -166.33 46.73\n{100} 7.61 -214.76 27.73\nFigure R19. (a) The simulated growth morphology of cocrystal 8&&111 based on the attachment energy. (b) The XRD pattern of cocrystal 8&11 (top) and simulated XRD pattern (bottom). (c) Schematics illustrations of the spatial relationships between the bending and top/side crystal planes.\nTable RR33.The simulated parameters of the growth morphology of cocrystal 8&11.\nhkl d (Å) E (kcal mol-1) Total facet area (%)\nhkl att\n{001} 11.30 -44.37 19.78\n{010} 9.74 -47.64 15.23\n{100} 9.03 -47.92 8.65\n{101} 8.72 -35.06 25.72\n{110} 8.06 -38.01 21.99\nFigure R2200. (a) The simulated growth morphology of cocrystal 1&&111 based on the attachment energy. (b) The XRD pattern of cocrystal 1&11 (top) and simulated XRD pattern (bottom). (c) Schematics illustrations of the spatial relationships between the bending and top/side crystal planes.\nTable R44..The simulated parameters of the growth morphology of cocrystal 1&11.\nhkl d (Å) E (kcal mol-1) Total facet area (%)\nhkl att\n{011} 9.85 -88.63 29.42\n{10-11}} 8.86 -74.14 10.55\n{020} 8.54 -75.30 18.14\n{110} 8.53 -98.38 13.17\n{11-11}} 7.86 -75.09 24.07\n{101} 6.80 -109.97 4.65\nRevision: The updated PXRD patterns have bbeeeenn provided in the revised supporting information. The sentencek  Single crystal data were obtained by the single crystal X-ray Diffraction (SCXRD) analysis. X-ray diffractions was carried out at 170 (2) K on a Bruker D8 VENTURE diffractometer using Mo-G‘ jY\\aYlagf '” : -+4.-40 v(+ Integration and scaling of intensity data were performed using the SAINT program. Data were corrected for the effects of absorption using SADABS. The structures were solved by direct method and refined with full-matrix least-squares technique using SHELX-2014 software. Non-hydrogen atoms were refined with anisotropic displacement parameters, and hydrogen atoms were placed in calculated positions and refined with a riding model. The molecular structure and configuration are analyzed by importing the corresponding CIF file into the Mercury software. The simulated growth morphology and crystal facet parameter are conducted based on single-crystal data by the Materials Studio software package. The PXRD patterns were measured through a D/max 2400 X-jYq\\a^^jY[lge]l]joal`?mG‘jY\\aYlagf'J = 1.54050 Å) operated in the /“ jYf_] ^jge 2y lg 1-y+‚ `Yn] Z]]f Y\\]\\ af l`] j]nak]\\ kmhhgjlaf_ af^gjeYlagf gf Pages S4 and S5.\n.0+ El ak mf^gjlmfYl]dq aehgkkaZd] lg [gee]fl gf l`] egd][mdYj \\qfYea[k ljYb][lgja]k afl`]hj]k]fl[Yk])_an]fl`]dY[cg^YfYdqkakhj]k]fl]\\afl`][mjj]fleYfmk[jahl)Yka\\] ^jge kge] \\a^^a[mdl*lg*mf\\]jklYf\\ kfYh k`glk+ Igj]gn]j) al ak g\\ lg k]] km[` keggl` ]f]j_q hjg^ad]k mfd]kk l`]j] ak kge] ka_fa^a[Yfl kl]]jaf_ af l`] I@ ljYb][lgja]k+ E^ l`] Yml`gjkYj]_gaf_lghj]k]flI@\\YlY)l`]j]f]]\\klgZ]em[`egj]YfYdqkak']+_+kge] YfYdqkak ZYk]\\ gf N@Bk Yf\\ [dmkl]j _jgol` YfYdqkak) ^j]] ]f]j_q YfYdqk]k) _l[( l`Yl [gmd\\ Zgl`]j [dYja^q l`] fYlmj] g^ l`] klm\\q l`Yl oYk \\gf]) Yf\\ Ydkg d]f\\ kge] imYfla^a[Ylagflgl`]\\YlY k]lk+\nResponse: Thank you for your insightful comments regarding the molecular dynamics simulations. In our case, the smoothness is a direct consequence of using a sufficiently small molecular dynamics time step. Consequently, the global energy trajectory appears smooth. It is conceptually similar to the mathematical principle that a sufficiently small, smooth segment of a curve can be approximated as linear (as in calculus). We acknowledge that a higher-resolution view would show the inherent fluctuations. The overall smooth profile, however, is a positive indicator of the stability and numerical accuracy of our simulations, rather than a sign of steering.\nThe primary objective of these particular MD simulations was to obtain a qualitative overview of the crystal growth trend and the corresponding energy changes, rather than a full quantitative mechanistic study. Given the significant computational cost associated with the free energy calculations and detailed analyses (such as RDFs and cluster growth analysis) mentioned by the reviewer, we have chosen to present the MD trajectories and basic energy plots in the Supplementary Information to support our main findings. Meanwhile, we have added the complete molecular dynamics simulation process of the slipped and bent structures to the revised Supporting Information (Figure R2211 and R22), which will help readers understand the entire process.\nFigure R2211. Molecular dynamics simulations of the nucleation process of slipped microstructures at different times. The solvent molecules are shown in wireframe pattern, and the assembled molecules are shown in a thicker ball and stick pattern.\nFigure R22. Molecular dynamics simulations of the nucleation process of bent microstructures at different times. The solvent molecules are shown in wireframe pattern, and the assembled molecules are shown in a thicker ball and stick pattern.\n.1+ P`] ]ph]jae]flYd Yf\\ kaemdYlagf \\]lYadk Yj] ^Yj ^jge Z]af_ km^^a[a]fl lg mf\\]jklYf\\) d]l Ydgf] j]hjg\\m[]) l`] j]kmdlk af l`] hYh]j+ P`]j] ak dalld]*llgg*fg \\]k[jahlagf g^ `go l`] emdlahd] `a]jYj[`a[Yd Z]f\\k o]j] afljg\\m[]\\ aflg l`] [jqklYdk+\nResponse: We sincerely thank the reviewer for this critical comment. We agree that providing sufficient experimental details is crucial for the reproducibility of the work.\nEf j]khgfk] lg l`ak [gee]fl) o] `Yn] l`gjgm_`dq j]nak]\\ l`]  Aph]jae]flYd @]lYadk‚ (now Section 11..4 and 11..5) in the Supplementary Information to include significantly more details regarding the synthesis of the hierarchical bent microcrystals.\nWe have now elaborated that the hierarchical bends are not introduced by external forces but emerge intrinsically during a kinetically controlled crystallization process. The substrate temperature and solution concentration are the key parameters that modulate the solvent evaporation rate and the supersaturation level, which in turn dictates the internal stress and the consequent bending degree of the crystals.\nEssentially, a higher temperature compromises the intermolecular interactions, which in turn increases the number of slip sites (Figure R23). This process promotes a greater number of bends within the structure (i.e., higher hierarchical order).\nFigure R23. Schematic illustration of the (I) temperature-triggered self-assembly slipping process and (II) concentration-driven self-assembly bending process.\nHoowwever, a higher temperature also accelerates the crystal growth rate. This rapid growth kinetics makes it extremely challenging to capture the intermediate states of higher-order slips (e.g., third or fourth slip), as these transitions occur too swiftly for our current in-situ characterization techniques to resolve. The key additions are as follows:\n(1) Synthesis of Hierarchically Slipped Microcrystals\nA solution of acceptor and donor molecules (1:1 molar ratio) in dichloromethane (DCM) oYk hj]hYj]\\ oal` Y [gf[]fljYlagf g^ / eegd Hð + P`]f) .- eH g^ l`ak klg[c kgdmlagf was rapidly injected into 10 mL of ethanol (EtOH). Immediately, 200 µL of the resulting mixture was drop-cast onto a pre-heated quartz substrate using a micropipette. The substrates were maintained at precise temperatures of 30 ± 0.2 °C and 32 ± 0.2 °C, respectively, using an electric temperature control platform. After complete solvent evaporation (typically within 5-7 minutes), the resulting microstructures were characterized. The slight difference in substrate temperature (30 vs. 32 °C) fine-tuned the self-assembly kinetics, leading to microcrystals with distinct single-slip (1-slip) and double-slip (2-slip) configurations, respectively.\n(2) Synthesis of Hierarchically Bent Microcrystals\n= egj] [gf[]fljYl]\\ klg[c kgdmlagf '2 eegd Hð(cid:143) af @?I) .7. egdYj jYlag g^ acceptor/donor) was used. Similarly, 10 mL of this solution was injected into 10 mL of EtOH. The mixture was drop-cast onto quartz substrates maintained at a series of precisely controlled temperatures: 30, 32, 34, 36, 38, and 40 °C (± 0.2 °C). After complete solvent evaporation, microstructures identified as 1-bend, 2-bend, 3-bend, 4-bend, 5-bend and 6-bend were observed on the respective substrates.\nRevision: The detailed experimental procedures (cid:129)A solution of acceptor and donor molecules (1:1 molar ratio) in dichloromethane (DCM) was prepared with a concentration of 2 mmol Hð(cid:143)+ P`]f) .- eH g^ l`ak klg[c kgdmlagf oYk jYha\\dq afb][l]\\ into 10 mL of ethanol (EtOH)~‚have been added on the pages S2 and S3 in the revised supplemental information.\n.2+ OlYlaf_ kaemdYlagfk o]j] h]j^gje]\\ ƒZq eYl]jaYdk klm\\ag„ ak fgl km^^a[a]fl+ S`Yl Yd_gjal`eko]j]mk]\\)Yf\\o`Ylo]j]l`]k]llaf_k<Igj]gn]j)l`]Yml`gjkf]]\\lg[dYja^q l`Yl l`]q \\a\\ fgl h]j^gje [jqklYd kljm[lmj] hj]\\a[lagf) Zml jYl`]j [jqklYd egjh`gdg_q hj]\\a[lagfk+ El ak fgl [d]Yj `go l`] Yml`gjk `Yn] eg\\]dd]\\ l`]aj [jqklYdk mkaf_ CYmkkaYf.3 'Y _Yk h`Yk] [g\\]() gj o`Yl l`]k] kaemdYlagfk Y[lmYddq o]j]+ El ak fgl [d]Yj o`YlYd_gjal`eoYkk]d][l]\\lg\\jan]fm[d]YlagfafI@kaemdYlagfk8fm[d]YlagfZ]af_Y jYj] ]n]fl mkmYddq f]]\\k Y ZaYk af l`] kaemdYlagfk kg E hj]kme] kge]l`af_ kaeadYj oYk f]]\\]\\ `]j]+ Kf] ogmd\\ fgl fgjeYddq ]ph][l Yf JRP kaemdYlagf lg j]kmdl af fm[d]Ylagf,[jqklYd_jgol`mfd]kkY\\jan]jgjgl`]jl`]jeg\\qfYea[ljYb][ljyqo]j]lgZ] afljg\\m[]\\ aflg l`] kaemdYlagf ']+_+) kdgodq j]egn] kgdn]fl egd][md]k) \\jan] l]eh]jYlmj])]l[(+O]] ]+_7 \\ga,.-+.--/,o[ek+.364+\nResponse: We greatly appreciate your constructive suggestions, which have helped us improve the clarity and rigor of our methodology section. We sincerely apologize for the lack of detailed information in our original manuscript regarding the simulation methods. S] ^mddq Y_j]] l`Yl klYlaf_  Zq IYl]jaYdk Olm\\ag‚ Ydgf] ak afkm^^a[a]fl+ P`] crystal morphology predictions were indeed performed using the Morphology module in Materials Studio, based on the attachment energy (Ežôô) model.[1] Typically, the molecular structure of the complex was firstly optimized based on the experimental [jqklYd kljm[lmj] '>mad\\ ’ >gf\\k ’ Ig\\md]k ’ Bgj[al] ’ ?Yd[mdYlagf ’ C]ge]ljq ghlaearYlagf ’ ?gehYkk ’ Nmf( Y^l]j aehgjlaf_ l`] [gjj]khgf\\af_ ?EB ^ad]) Yf\\ l`] geometric and energy calculations were performed using the Forcite and Morphology eg\\md]k'Ig\\md]k’Igjh`gdg_q’?Yd[mdYlagf’Cjgol`egjh`gdg_q’Compass ’ Nmf(+ P`]fl`] hj]\\a[l]\\ _jgol` egjh`gdg_q g^ l`] [jqklYdk Yf\\ l`] [gjj]khgf\\af_ attachment energies were obtained.\nGaussian 16 was employed only for geometry optimization of individual molecules, not used for modeling periodic crystals or solid-state simulations. Molecular dynamics simulations were performed with the Forcite software package. The Universal Forcefield (UFF)[2] was used as the energy expression of phase energy surface (PES). The Qeq method[3]was applied to assign the atomic charge with the tolerance of 5×10-4 e. The non-bond interaction was evaluated by the Ewald method[4] with the Ewald accuracy of 10-5 kcal/mol. During the optimization process, all the atoms were allowed to relax. The convergence criteria for energy change are 2×10-5 kcal/mol and for force is 0.001 kcal/mol/Å. After the geometry optimization, a 1 ns of NVT MD simulation was performed. The data was collected in the production phase for 90 ns. The Andersen method[5] was used to maintain the temperature during the simulation. In our simulations, a gentle traction force (a very small resonant force) was applied to facilitate the initial formation of the crystal nucleus.[6] The equilibrium position for the traction force was set at an interplanar distance of 3.65 Å. At this distance, the traction force is zero, and an attractive force is applied at distances greater than this value. The force constant was set to a small value of 0.0572 kcal/(mol·Å2). The key parameters of equilibrium position and force constant for this bias were derived from quantum chemical calculations to ensure physical relevance, which provides a slight thermodynamic driving force to promote nucleation, while being weak enough lg eafaear] h]jlmjZYlagf g^ l`] kqkl]e„k fYlmjYd \\qfYea[k Yf\\ Ynga\\ afljg\\m[af_ fgf-physical artifacts into the simulation trajectory.\nReferences\n[1] J. Feng, Z. Q. Yao, M. Sun, J. Yang, C. Z. Wang, S. H. Chen, H. T. Lin, Y. Z. Cheng, Q. Lv, X. D. Wang, Aimed synthesis of organic alloys and heterostructures via precision-tailored routes. Chin. J. Chem.2025, 43, 2104(cid:127)2110.\n[2] A. K. Rappé, C. J. Casewit, K. S. Colwell, W. A. Goddard III, W. M. Skiff, UFF, a full periodic table force field for molecular mechanics and molecular dynamics simulations. J. Am. Chem. Soc. 1992, 114, 10024(cid:127)10035.\n[3] A. K. Rappe, W. A. Goddard III, Charge equilibration for molecular dynamics simulations. J. Phys. Chem.1991, 95, 3358(cid:127)3363.\n[4] N. Karasawa, W. A. Goddard III, Acceleration of convergence for lattice sums. J. Phys. Chem.1989, 93, 7320(cid:127)7327.\n[5] H. C. Andersen, Molecular dynamics simulations at constant pressure and/or temperature. J. Phys. Chem. 1980, 72, 2384(cid:127)2393.\n[6] A. R. Finney, M. Salvalaglio, Molecular simulation approaches to study crystal nucleation from solutions: Theoretical considerations and computational challenges. Wires. Comput. Mol. Sci.2024, 14, e1697.\nRevision: The detailed theoretical calculation methods have been added in the revised Omhhd]e]flYjq Ef^gjeYlagf+ (cid:129)CYmkkaYf .3 oYk ]ehdgq]\\ gfdq ^gj _]ge]ljq optimization of individual molecules, not used for modeling periodic crystals or solid-state simulations. Molecular dynamics simulations were performed with the Forcite software package. The Universal Forcefield (UFF)2 was used as the energy expression of phase energy surface (PES). The Qeq method3 was applied to assign the atomic charge with the tolerance of 5×10-4 e. The non-bond interaction was evaluated by the Ewald method4 with the Ewald accuracy of 10-5 kcal/mol. During the optimization process, all the atoms were allowed to relax..+‚P`][gjj]khgf\\af_j]^]j]f[]`Yn]Z]]f added on the page S31 in the revised supplemental information.\nComment from Reviewer 2:\nIn my view the authors have done a nice job of addressing the reviewer comments, which have drastically improved the manuscript. I am happy with the modifications that they have made, but have a final query, which I think is essential in order to justify the paper’s publication in nature commun.\nThe idea of growing bent crystals is certainly not new, and has been reported a number of times. This is often due to the emergent growth of a twin (e.g., https://gelogia.com/crystal-twinning/; https://www.sciencedirect.com/science/article/pii/002202489500419X), which gives rise to macroscopic appearance of a bent (or twisted) single crystals, for example:\nGrowth-actuated twisting/bending (2014): https://onlinelibrary.wiley.com/doi/full/10.1002/anie.201301223\nTautomerism induces bending and twisting of biogenic crystals (2025): https://www.pnas.org/doi/10.1073/pnas.2426814122\nAnomalous twin boundaries in two dimensional materials (2018): https://www.nature.com/articles/s41467-018-06074-8\nIn fact, the exact orientation of relative domains in such ‘bent’ crystals have been studied in some detail using advanced imaging methods in some cases (e.g., 2016: https://www.nature.com/articles/srep28651)\nI would like to see the authors justify their findings in light of previous similar findings, either to solidify the proposed mechanisms or to establish the novelty of their own findings.\nResponse: We thank the reviewer for their positive assessment of our revisions and for raising this important point regarding the relationship between our work and prior studies on twin-mediated crystal bending. We agree that crystal bending via twinning is a well-documented phenomenon, and we appreciate the opportunity to clarify how our findings both build upon and distinctively advance this established body of knowledge.\nWhile previous studies, such as the classical Wagner–Hamilton–Seidensticker (WHS) model for FCC crystals, growth-actuated twisting in biogenic systems, and twin-boundary characterization in 2D materials, have demonstrated that twin formation can yield macroscopic bending, these works largely focus on the morphological outcomes or idealized models of twin interfaces. In contrast, our study provides an nanoscale mechanistic understanding of bending in molecular organic crystals, achieved through a non-twinning pathway that has not been previously reported.\nSpecifically, our work advances the field in the following key aspects:\n(i) A Non-Twinning Slip–Rotation Mechanism: Unlike classical twin-mediated bending, where the bending arises from symmetrical growth along a pre-existing twin plane, the bending in our system results from an artificially triggered slip–rotation process. We deliberately exploited anisotropic non-covalent interactions and used a curved substrate under controlled thermal conditions to induce asymmetric growth and progressive slip accumulation. Once the interfacial stress reached a critical threshold, the accumulated strain was released by spontaneous block rotation along predefined slip planes, leading to a stable bent configuration with a well-defined angle. This process begins with a straight one-dimensional single crystal and ends with a controlled bend, fundamentally differing from growth patterns initiated by twin boundaries.\n(ii) Lattice Preservation: In conventional twinning, lattice deformation or reorientation at the boundary often occurs, which can compromise functional properties. In our system, bending proceeds via the rotation of rigid molecular blocks without continuous lattice distortion. This preserves the original molecular packing within each block and avoids introducing strain. As a result, the crystal lattice at the bending interface remains coherent and undeformed, enabling the retention of uniform optical properties, a crucial advantage for applications in organic optoelectronics.\n(iii) Bridging the Gap Between Organic and Inorganic Crystals: Our findings reveal that crystal bending can be achieved in organic materials through a mechanism distinct from those observed in inorganic or biogenic systems. While established crystallographic concepts (e.g., twinning) remain relevant, the manifestation in molecular crystals is uniquely governed by anisotropic intermolecular interactions and molecular flexibility. This offers a new mechanistic framework for designing organic semiconductors, where strain-free bending is desirable for retaining electronic and optical performance.\nIn summary, our work uncovers a previously unreported bending pathway in molecular crystals that is fundamentally different from twin-mediated deformation. By providing real-space mechanistic insight into a slip- and rotation-driven process, and demonstrating its benefit for functional property retention, we establish a novel principle for achieving and tailoring curvature in crystalline materials, with implications for the design of molecular photonic/electronic devices."}, {"round": 2, "reviewer_comments": {"reviewer_1": "The authors have addressed the queries and suggestions in the revised version. Therefore, I recommend the publication of this paper.", "reviewer_2": "In my view the authors have done a nice job of addressing the reviewer comments, which have drastically improved the manuscript. I am happy with the modifications that they have made, but have a final query, which I think is essential in order to justify the paper's publication in nature commun.\nThe idea of growing bent crystals is certainly not new, and has been reported a number of times. This is often due to the emergent growth of a twin (e.g., https://gelogia.com/crystal-twinning/; https://www.sciencedirect.com/science/article/pii/002202489500419X), which gives rise to macroscopic appearance of a bent (or twisted) single crystals, for example:\n* Growth-actuated twisting/bending (2014): https://onlinelibrary.wiley.com/doi/full/10.1002/anie.201301223\n* Tautomerism induces bending and twisting of biogenic crystals (2025):\nhttps://www.pnas.org/doi/10.1073/pnas.2426814122\n* Anomalous twin boundaries in two dimensional materials (2018): https://www.nature.com/articles/s41467-018-06074-8\nIn fact, the exact orientation of relative domains in such 'bent' crystals have been studied in some detail using advanced imaging methods in some cases (e.g., 2016: https://www.nature.com/articles/srep28651)\nI would like to see the authors justify their findings in light of previous similar findings, either to solidify the proposed mechanisms or to establish the novelty of their own findings."}, "author_response": "We thank the reviewer for their positive assessment of our revisions and for raising this important point regarding the relationship between our work and prior studies on twin-mediated crystal bending. We agree that crystal bending via twinning is a well-documented phenomenon, and we appreciate the opportunity to clarify how our findings both build upon and distinctively advance this established body of knowledge.\nWhile previous studies, such as the classical Wagner–Hamilton–Seidensticker (WHS) model for FCC crystals, growth-actuated twisting in biogenic systems, and twin-boundary characterization in 2D materials, have demonstrated that twin formation can yield macroscopic bending, these works largely focus on the morphological outcomes or idealized models of twin interfaces. In contrast, our study provides an nanoscale mechanistic understanding of bending in molecular organic crystals, achieved through a non-twinning pathway that has not been previously reported.\nSpecifically, our work advances the field in the following key aspects:\n(i) A Non-Twinning Slip–Rotation Mechanism: Unlike classical twin-mediated bending, where the bending arises from symmetrical growth along a pre-existing twin plane, the bending in our system results from an artificially triggered slip–rotation process. We deliberately exploited anisotropic non-covalent interactions and used a curved substrate under controlled thermal conditions to induce asymmetric growth and progressive slip accumulation. Once the interfacial stress reached a critical threshold, the accumulated strain was released by spontaneous block rotation along predefined slip planes, leading to a stable bent configuration with a well-defined angle. This process begins with a straight one-dimensional single crystal and ends with a controlled bend, fundamentally differing from growth patterns initiated by twin boundaries.\n(ii) Lattice Preservation: In conventional twinning, lattice deformation or reorientation at the boundary often occurs, which can compromise functional properties. In our system, bending proceeds via the rotation of rigid molecular blocks without continuous lattice distortion. This preserves the original molecular packing within each block and avoids introducing strain. As a result, the crystal lattice at the bending interface remains coherent and undeformed, enabling the retention of uniform optical properties, a crucial advantage for applications in organic optoelectronics.\n(iii) Bridging the Gap Between Organic and Inorganic Crystals: Our findings reveal that crystal bending can be achieved in organic materials through a mechanism distinct from those observed in inorganic or biogenic systems. While established crystallographic concepts (e.g., twinning) remain relevant, the manifestation in molecular crystals is uniquely governed by anisotropic intermolecular interactions and molecular flexibility. This offers a new mechanistic framework for designing organic semiconductors, where strain-free bending is desirable for retaining electronic and optical performance.\nIn summary, our work uncovers a previously unreported bending pathway in molecular crystals that is fundamentally different from twin-mediated deformation. By providing real-space mechanistic insight into a slip- and rotation-driven process, and demonstrating its benefit for functional property retention, we establish a novel principle for achieving and tailoring curvature in crystalline materials, with implications for the design of molecular photonic/electronic devices."}]

Decision letter