AndreaBozzo/ceres-open-data-index huggingface dataset:
First-principles electron-phonon interactions and polarons in the parent cuprate La₂CuO₄

Understanding electronic interactions in high-temperature superconductors is an outstanding challenge. In the widely studied cuprate materials, experimental evidence points to strong electron-phonon (e-ph) coupling and broad photoemission spectra. Yet, the microscopic origin of this behavior is not fully understood. Here we study e-ph interactions and polarons in a prototypical parent (undoped) cuprate, La₂CuO₄ (LCO), by means of first-principles calculations. Leveraging parameter-free Hubbard-corrected density functional theory, we obtain a ground state with band gap and Cu magnetic moment in nearly exact agreement with experiments. This enables a quantitative characterization of e-ph interactions. Our calculations reveal two classes of longitudinal optical (LO) phonons with strong e-ph coupling to hole states. These modes consist of Cu-O plane bond-stretching and bond-bending as well as vibrations of apical O atoms. The hole spectral functions, obtained with a cumulant method that can capture strong e-ph coupling, exhibit broad quasiparticle peaks with a small spectral weight (Z≈0.25) and pronounced LO-phonon sidebands characteristic of polaron effects. Our calculations predict features observed in photoemission spectra, including a 40-meV peak in the e-ph coupling distribution function not explained by existing models. These results show that the universal strong e-ph coupling found experimentally in lanthanum cuprates is an intrinsic feature of the parent compound, and elucidates its microscopic origin.

Tags: dftu, electron-phonon-coupling, hubbard-u, marvel, parent-cuprate, phonons, polarons, spectral-function
Ab-initio simulation of liquid water without artificial high temperature

Comprehending the structure and dynamics of water is crucial in various fields such as water desalination, ion separation, electrocatalysis, and biochemical processes. While reported works show that the ab-initio molecular dynamics (AIMD) can accu- rately portray water's structure, the artificial high temperature (AHT) from 120K to 30K is needed to mimic the quantum nature of hydrogen-bond network from GGA, metaGGA to hybrid functionals. The AHT proves to be an inadequate approach for systems involving aqueous multiphase mixtures, such as water-solid interfaces and aque- ous solutions. This is due to the activation of additional phonons in other phases, which can lead to an overestimation of the dynamics for nearby water molecules. In this work, we find the regularized SCAN (rSCAN) functional can well capture both the structure and dynamics of liquid water at ambient conditions without AHT. Moreover, rSCAN can well match the experimental results of hydration structures for alkali, alkali earth and halide ions. We anticipate that the versatile and accurate rSCAN functional will emerge as a key tool based on ab-initio simulation for investigating chemical processes in aqueous environments.

Tags: aimd, density-functional-theory, machine-learning-potential, metagga, water
Substrate-aware computational design of two-dimensional materials

Two-dimensional (2D) materials have attracted considerable attention due to their remarkable electronic, mechanical and optical properties, making them prime candidates for next-generation electronic and optoelectronic applications. Despite their widespread use in combination with substrates in practical applications, including the fabrication process and final device assembly, computational studies often neglect the effects of substrate interactions for simplicity. 
In this record, we provide the results of the computational study of the stable 2D molybdenum-sulfur (Mo-S) structures on a c-cut sapphire (Al₂O₃). In particular, we provide the results of the evolutionary search in the Mo-S / Al₂O₃ (0001) system, the machine learning interatomic potential (MLIP) used for local relaxation of the systems during the evolutionary search together with its training set, post-processing data on electronic and phonon band structures of the stable 2D Mo-S structures, and the predicted stability patterns from the perspective of CVD synthesis.

Tags: 2d-materials, crystal-structure-prediction, machine-learning
REFPU Domaine Public Adopté (Surface)

Le référentiel des projets urbains (RefPU) est la version numérique des plans d'affectations produits par l'autorité compétente en matière d'aménagement du territoire du canton de Genève. Pour l'heure, seuls les plans localisés de quartier (PLQ) sont publiés dans ce référentiel. A terme, les modifications de zone (MZ) ainsi que les plans directeurs de zones industrielles (PDZI), mais aussi les plans de site (PS) produits par l'office du patrimoine et des sites, pourraient également y être publiés. La thématique RefPU permet de consulter l'ensemble des données géographiques et alphanumériques contenues dans un PLQ et de les mettre en regard avec d'autres données territoriales issues d'autres politiques publiques ou des données de référence (limites communales, cadastre, courbes de niveau, etc.). Les PLQ publiés sur ce thème font l'objet d'une consultation publique, conformément aux exigences légales en vigueur. Les données qu'ils contiennent sont mises à la disposition des partenaires du SITG et consultables sur ce guichet. Néanmoins, hormis le périmètre de validité d'un plan adopté qui a une valeur légale contraignante, les autres données géographiques et alphanumériques mises à disposition, ne créent aucun autre droit ou obligation que ceux découlant des textes et documents légalement mis en procédure, adoptés et publiés. En premier lieu, le RefPU permet de géoréférencer chaque plan, et par extension, chacun des éléments constitutifs du plan. Il offre également une unicité de représentation graphique standardisée pour l'ensemble des plans localisés de quartier grâce à une charte graphique et un modèle de données géomatique uniformisés. La thématique RefPU offre également la possibilité de représenter simultanément dans une carte numérique l'ensemble des PLQ numérisés sur tout le territoire genevois. Grand avantage par rapport au format papier ou pdf, le guichet numérique permet d'interroger la valeur de chaque donnée contenue dans une couche du modèle. Note: tout comme sur un plan en format papier ou pdf, les PLQ numériques se composent d'un plan d'aménagement et d'un plan des équipements, distincts. Les deux plans peuvent être consultés séparément.
Quantum correlation of channel-confined ions in graphene-based transistors for energy-efficient neuromorphic chips

Based on ab initio molecular dynamics simulations, we explain how graphene-based ion transistors work, using channels filled with K⁺ ions. Our results show that electrons in graphene allow confined ions to influence each other over long distances. This explains why the transistor responds sensitively to changes in ion density, which are controlled by the gate voltage. The ON/OFF switching behavior comes from the competition between π–π stacking and cation–π interactions, which changes with ion density. The increase in ion transport efficiency—also called signal amplification—is caused by the ions moving together in a coordinated way that depends on their density. Additionally, when ions outside the channel resonate with those inside, rapid dehydration occurs. This leads to very fast ion movement through the transistor. These atomic-scale insights can help guide the design of future ultra-low-energy neuromorphic chips.

Tags: --stacking, cation-2-interaction, collective-ion-oscillation, ion-transistor, ionics
Assessing the accuracy of exchange-correlation functionals in density functional theory for hydrogen-benzene and hydrogen-hydrogen interactions

We calculated the interaction energies of hydrogen-benzene and hydrogen-hydrogen complexes using dispersion-inclusive exchange-correlation functionals in density functional theory and compared them with results from the coupled cluster method with single, double, and perturbative triple excitations and those from the adiabatic-connection fluctuation-dissipation theorem within the random phase approximation. For both complexes, the recent generations of nonlocal van der Waals density functionals show overall improvement over semilocal exchange-correlation functionals with dispersion corrections, yielding good agreement with the coupled cluster method. We discuss their accuracy and recommend suitable exchange-correlation functionals based on different evaluation metrics.

Tags: beef, beef-vdw, benzene, ccsdt, cof, dft, hydrogen, hydrogen-storage, lda, mof, molgw, optb86b-vdw, optb88-vdw, orca, pbe, pbe-d3, pbesol, pbesol-d3, quantum-espresso, r2scan, r2scan-rvv10, rev-vdw-df2, rpa, rpbe, rpbe-d3, rvv10, scan, scan-rvv10, vasp, vdw-df, vdw-df-cx, vdw-df2, vdw-df3-opt1, vdw-df3-opt2
OCV intercalation workflow implemented across DFT and workflow engines

Dataset: Interoperable DFT OCV Workflows (Final Alignment)









We present a dataset enabling cross‑engine alignment and reproducibility of open‑circuit voltage (OCV) calculations for battery cathode materials within standardized density functional theory (DFT) workflows. The dataset implements a common, JSON‑based input/output schema and a semantic JSON‑LD description to express the workflow’s scientific intent, inputs, methods, and outputs in a code‑agnostic manner, supporting FAIR reuse. Using shared OPTIMADE‑style input structures, we execute an identical OCV protocol across multiple workflow managers and DFT engines (VASP via PerQueue and SimStack, GPAW, Quantum ESPRESSO, and CASTEP). Engine‑specific archives provide standardized output JSON files for cross‑comparison, and, where available, native files to enable full reproduction.

We focus on five representative cathode chemistries (Li2Mn3NiO8, LiCoO2, LiTiS2, LiFePO4, and MgMo3S4), chosen to probe diverse structural and electronic regimes. The dataset documents strong cross‑engine agreement for average OCVs derived from pristine charged/discharged cells, and highlights where alignment is challenging, notably for vacancy‑containing supercells at low/high states of charge due to sensitivity to smearing, symmetry breaking, and optimization procedures. By releasing harmonized inputs, standardized outputs, and semantic metadata, this work provides a practical resource for benchmarking interoperable DFT workflows, facilitates transparent comparison across codes, and supports reproducible studies and future extensions (e.g., spin polarization and Hubbard corrections) in high‑throughput materials discovery.

Tags: battery, big-map, dft, ocv, workflows
Search for low-periodic substructures in crystalline solids: a novel approach

This record contains the two-dimensional substructures identified using a novel  approach based on the crystal graph construction via Voronoi partition, interaction strength estimation via bond valence theory and the iterative removal of weak links, strating from experimentally known bulk compounds. We also report the results of DFT calculations on a subset of newly identified easily exfoliable and robust two-dimensional materials.

Tags: 2d-materials, electronic-bands, high-throughput
Critical role of phase-dependent properties in modeling photothermal sintering of LiCoO2 cathodes

Photothermal (photonic) sintering crystallizes as-deposited amorphous LiCoO2 (LCO) cathodes for solid-state thin-film batteries using millisecond, surface-localized heating. However, process design often relies on 1D models with phase-averaged, temperature-independent properties, which can mispredict peak temperatures and thermal damage margins. Here we develop a multiscale, data-driven framework that provides phase- and grain-size–resolved thermophysical inputs for stoichiometric LCO. We train an Allegro neural network potential with near-ab initio accuracy, enabling Green–Kubo calculations of thermal conductivity for crystalline and amorphous phases. The low, weakly density-dependent conductivity of amorphous LCO motivates its use as an effective intergranular phase in a thin-interface model that reproduces observed grain-size–dependent thermal transport. Combined with measured wavelength-resolved optical properties in 1D multiphysics simulations, we show amorphous LCO absorbs more strongly and reaches higher peak temperatures than crystalline LCO; thus crystalline, constant-property models systematically overestimate safe operating windows.

Tags: heat-transfer, licoo2, marvelp1, molecular-dynamics, neural-network-potential, photonic-sintering, thermal-conductivity
Electronic structure and dynamical correlations in antiferromagnetic BiFeO3

We study the electronic structure and dynamical correlations in antiferromagnetic BiFeO3, a prototypical room-temperature multiferroic, using a variety of static and dynamical first-principles methods. Conventional static Hubbard corrections (DFT+U, DFT+U+V) incorrectly predict a deep-valence Fe 3d peak (around -7 eV) in antiferromagnetic BiFeO3, in contradiction with hard-X-ray photoemission. We resolve this failure by using a recent generalization of DFT+U to include a frequency-dependent screening – DFT+U(ω) – or using a dynamical Hubbard functional (dynH). The screened Coulomb interaction U(ω), computed with spin-polarized RPA and projected onto maximally localized Fe 3d Wannier orbitals, is expressed as a sum-over-poles, yielding a self-energy that augments the Kohn–Sham Hamiltonian. This DFT+U(ω) approach predicts a fundamental band gap of 1.53 eV, consistent with experiments, and completely eliminates the unphysical deep-valence peak. The resulting simulated HAXPES spectrum reproduces the experimental lineshape with an accuracy comparable to state-of-the-art approaches. Our work highlights the critical nature of dynamical screening in complex oxides and of DFT+U(ω) as a predictive and computationally efficient approach to address the electronic structure of correlated materials.

Tags: density-functional-theory, dynamical-correlations, electronic-structure
Lattice dynamics and structural phase stability of group IV elemental solids with the r²SCAN functional

The strongly constrained and appropriately normed (SCAN) meta-GGA functional is a milestone achievement of electronic structure theory. Recently, a revised and restored form (r²SCAN) has been suggested as a replacement for SCAN in high-throughput applications. Here, we assess the accuracy and reliability of the r²SCAN meta-GGA functional for the group IV elemental solids carbon (C), silicon (Si), germanium (Ge), and tin (Sn). We show that the r²SCAN functional agrees closely with its parent functional SCAN for elastic constants, bulk moduli, and phonon dispersions, but the numerical stability of r²SCAN is superior. Both meta-GGA functionals outperform standard GGA (Perdew-Burke-Ernzerhof) in terms of accuracy and approach the level of common hybrid functionals (Heyd-Scuseria-Ernzerhof). However, we find that r²SCAN performs much worse than SCAN for the α ↔ β phase transition of both Ge and Sn, yielding larger phase energy differences and transition pressures.Here we make available the raw phonon dispersion data and VASP input files for an example phonon calculation.

Tags: dft, phonons, vasp
Interlayer hydrogen-hydrogen spacing regulates the formation of molecular hydrogen in hydrogen boride nanosheets

Hydrogen carriers that enable efficient transport and on-demand release of molecular hydrogen (H2) are crucial for practical hydrogen-based energy systems. Hydrogen boride (HB) nanosheets, composed of boron and hydrogen in a 1:1 stoichiometric ratio, have promising potential as safe and lightweight hydrogen carriers owing to their high gravimetric hydrogen density (8.5 wt %). In particular, heating of HB nanosheets results in H2 release over a broad temperature range from 423 to 1473 K. However, the mechanism of the multimodal H₂ desorption remains unclear. In this work, we elucidate that the interlayer H···H distances (dH···H) determine the multimodal desorption of H2 especially in the lower-temperature range (< 623 K). HB nanosheets subjected to various temperatures under different H2 pressures were prepared to investigate the thermal stability of their bonding configurations. Infrared spectroscopy and temperature-programmed desorption measurements revealed the occurrence of hydrogen depletion while the bonding configuration remains unchanged. The first to third nearest dH···H, along with the numbers of the corresponding H···H pairs, were systematically calculated for four possible interlayer stacking types. The calculated H···H pairs distribution closely matched the experimental profile for the thermally induced H2 desorption, suggesting that the multimodal desorption of H2 in the lower-temperature range is governed by the distribution of hydrogen distances. This study elucidates the unique mechanisms of H2 formation in HB nanosheets and provides valuable insights into the design of two-dimensional hydrogen containing materials.

Tags: hydrogen-boride-nanosheet, hydrogen-release, interlayer-space, two-dimensional-materials
Machine-learning-enabled ab initio study of quantum phase transitions in SrTiO3

We use the self-consistent harmonic approximation (SSCHA) with machine learning interatomic potentials to calculate the effect of 18O substitution on the properties of quantum paraelectric SrTiO3 (STO). We find that calculations including both quantum and anharmonic effects are able to reproduce the experimentally observed isotope effect, in which the replacement of 16O by 18O induces the ferroelectric state, and we demonstrate that the ferroelectric phase transition in ST18O can be reproduced in a purely displacive description. We calculate the ferroelectric soft mode frequency as a function of volume, lattice parameters, and temperature for ST16O and ST18O and find that the phase space in which ST16O shows quantumparaelectric behavior, while ST18O becomes ferroelectric, is narrow. Our Letter shows that machine learning interatomic potentials enable temperature-dependent simulations that include quantum and anharmonic phonon effects and that quantitative prediction of the phase diagram in the case of STO is limited by the accuracy of the underlying electronic structure method.

This dataset contains the inputs/and outputs from the SSCHA calculations.

Tags: ferroelectric, isotope-effect, quantum-paraelectric, srtio3
Importance of nonlinear long-range electron-phonon interaction on the carrier mobility of anharmonic halide perovskites

Electron-phonon interactions in a solid are crucial for understanding many interesting material properties, such as transport properties and the temperature dependence of the electronic band gap. For harmonic materials, the linear interaction process where one electron interacts with one phonon is sufficient to quantitatively describe these properties. However, this is no longer true in anharmonic materials with significant electron-phonon interaction, such as halide perovskites. Currently, the only available models for nonlinear electron-phonon interaction are model Hamiltonians, written in terms of phenomenological parameters. Here, we provide a postprocessing Python code for the treatment of the long-range part of the 1-electron-2-phonon interaction. We show in the associated manuscripts that it is sufficient to know the phonon frequencies and eigenvectors calculated at a finite electric field, which we provide alongside this software for three selected materials: LiF, KTaO3, and CsPbI3. We calculate the 1-electron-2-phonon spectral functions for these materials, and use the one for CsPbI3 to calculate the contribution of the 1-electron-2-phonon interaction to the electron mobility. We show that the nonlinear interaction contributes significantly to the temperature scaling of the mobility in CsPbI3, due to its low phonon frequencies. For LiF, a very harmonic material with high phonon frequencies, the effect is negligible as expected. In KTaO3 the effect of nonlinear interaction is also negligible, despite the fact that it is an anharmonic material: this is due to the fact that it also has high phonon frequencies.

Tags: anharmonicity, electron-phonon-coupling, first-principles, transport
Modulus and yield strength determination at ultra-thin atomic layer deposited hydroxylated alumina coatings using spherical nanoindentation and surface acoustic waves

Mechanical properties of ultrathin coatings can deviate from bulk values due to growth-stage and interface effects. Elastic moduli of bulk amorphous alumina were calculated using a near-ab initio-accurate neural-network interatomic potential to provide a modeling benchmark for hydroxylated alumina coatings deposited by atomic layer deposition at 50 °C. Experimentally, elastic moduli were evaluated by both spherical nanoindentation and laser-induced surface acoustic wave spectroscopy (LiSAWS). For coatings thicker than 7 nm, both techniques indicated a weakly decreasing modulus from ~137 GPa to ~126 GPa (nanoindentation) and ~116 GPa to ~108 GPa (LiSAWS). These values are consistent with the simulated Young’s modulus.

Tags: atomic-layer-deposition-ald, foundation-model, hydroxylated-alumina, laser-induced-surface-acoustic-wave-spectroscopy-lisaws, marvelp1, molecular-dynamics, spherical-nanoindentation, ultrathin-coatings, yield-strength, youngs-modulus
Vibrational frequencies and stark tuning rate with continuum electro-chemical models and grand canonical density functional theory

This archive provides the AiiDA workflows, metadata, and computational datasets associated with the study of vibrational frequencies and Stark tuning rates at electrochemical interfaces within the framework of grand-canonical density functional theory (GC-DFT) combined with continuum electrochemical models.

In this work, the electrochemical potential is treated as a degree of freedom by adjusting the number of electrons in the Kohn-Sham equations, enabling simulations at fixed potential. Based on the relationship between free energy and grand potential, physical properties such as atomic forces, vibrational frequencies, and Stark tuning rates are consistently evaluated. While atomic forces are found to be equivalent to Hellmann-Feynman forces in the canonical ensemble, vibrational frequencies and Stark tuning rates exhibit distinct behavior under grand-canonical conditions.

The archive contains input parameters, workflows, and computed results obtained using finite-displacement methods for the evaluation of vibrational properties and Stark tuning rates. These data enable the reproduction of the results reported in the associated publication and provide a reference for future studies of electrochemical interfaces under constant potential conditions.

Tags: grand-canonical-dft, stark-tuning-rate, vibrational-frequencies
Ternary phase diagram of nitrogen doped lutetium hydrides

This dataset presents the results of a comprehensive crystal structure search for ternary compounds in the Lu–N–H system. Thousands of candidate structures were evaluated, and their thermodynamic stability was assessed through the construction of the convex hull of formation enthalpies. To ensure reliable energetic ordering, all calculations were performed using the highly accurate r2SCAN density functional in an all-electron framework, avoiding possible pseudopotential-related inaccuracies.  A previously unreported lutetium hydride phase (HLu₂) is identified on the convex hull, indicating thermodynamic stability. However, subsequent electron–phonon coupling analysis shows that this structure is not a promising candidate for near-ambient superconductivity. Apart from this additional phase, the results are in close agreement with earlier structure prediction studies, demonstrating strong reproducibility across independent computational approaches. This consistency highlights the maturity and reliability of modern crystal structure prediction methods. Overall, the dataset provides further evidence that no thermodynamically stable structure within the Lu–N–H system is likely to exhibit conventional high-temperature superconductivity under near-ambient conditions, as would be required to explain previously reported experimental claims.

Tags: dft, minimahopping, superconductor