jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Shuaihua Lu | Luca M. Ghiringhelli | Christian Carbogno | Jinlan Wang | Matthias Scheffler
Source: arXiv (Cornell University) (preprint, 2023-09-01)
Field: Materials Science — Materials Chemistry

On the Uncertainty Estimates of Equivariant-Neural-Network-Ensembles Interatomic Potentials Machine-learning (ML) interatomic potentials (IPs) trained on first-principles datasets are becoming increasingly popular since they promise to treat larger system sizes and longer time scales, compared to the {\em ab initio} techniques producing the training data. Estimating the accuracy of MLIPs and reliably detecting when predictions become inaccurate is key for enabling their unfailing usage. In this paper, we explore this aspect for a specific class of MLIPs, the equivariant-neural-network (ENN) IPs using the ensemble technique for quantifying their prediction uncertainties. We critically examine the robustness of uncertainties when the ENN ensemble IP (ENNE-IP) is applied to the realistic and physically relevant scenario of predicting local-minima structures in the configurational space. The ENNE-IP is trained on data for liquid silicon, created by density-functional theory (DFT) with the generalized gradient approximation (GGA) for the exchange-correlation functional. Then, the ensemble-derived uncertainties are compared with the actual errors (comparing the results of the ENNE-IP with those of the underlying DFT-GGA theory) for various test sets, including liquid silicon at different temperatures and out-of-training-domain data such as solid phases with and without point defects as well as surfaces. Our study reveals that the predicted uncertainties are generally overconfident and hold little quantitative predictive power for the actual errors. Maxima and minima ; Computer science ; Robustness (evolution) ; Artificial neural network ; Artificial intelligence ; Training set ; Correlation ; Machine learning ; Algorithm ; Statistical physics ; Mathematics ; Physics ; Chemistry Machine Learning in Materials Science ; Electron and X-Ray Spectroscopy Techniques ; Thermal properties of materials
Authors: Yuya Kakiuchi | Svetlana Shapovalova | Bogdan Protsenko | С. А. Гуда | Оlga V. Safonova | Alexander A. Guda | Christophe Copéret
Source: ChemRxiv (preprint, 2023-08-08)
Field: Materials Science — Materials Chemistry

Influence of Strong pi-Acceptor Ligands on Cr-K-edge X-Ray Absorption Spectral Signatures and Consequences on Interpretation of Surface Sites in the Phillips Catalyst X-ray absorption spectroscopy (XAS) is one of the most powerful characterization techniques, that has been intensively employed to study the Phillips polymerization catalyst (CrO3/SiO2). While Cr K-edge XAS signatures are used to evaluate the nature of surface (active) sites, they are highly sensitive to oxidation state, geometry and types of ligands, making interpretation challenging. In the specific case of CrO3/SiO2, CO has been particularly used both as a reductant to generate the expected low valent Cr sites and a probe to understand surface Cr sites. Considering the electronic properties of CO, a strong s-donor and pi-acceptor ligand, one may wonder the impact of the coordination of CO on Cr on its XAS signature. We herein built a molecular low-valent Cr library bearing isocyanide ligands, which mimic CO as its isoelectronic counterpart, as a model of low-valent Cr sites interacting with p-acceptor ligand. Cr K-edge XAS augmented with DFT calculations elucidated the profound effect of isocyanide ligand on both XANES and EXAFS regions giving a rise to characteristic features as well as the significant stabilization of low-spin Cr(II/III) species, which potentially alter the ease of interpretation of XAS spectra. Taking the herein demonstrated effect of p-acceptor ligand into account, experimental Cr K-edge spectra of CO-reduced Phillips catalyst at different temperatures were reproduced show-casing the effect of CO on Cr sites. X-ray absorption spectroscopy ; XANES ; Chemistry ; Absorption spectroscopy ; Ligand (biochemistry) ; Acceptor ; Extended X-ray absorption fine structure ; Crystallography ; Spectroscopy ; Physics Machine Learning in Materials Science ; X-ray Spectroscopy and Fluorescence Analysis ; Organometallic Complex Synthesis and Catalysis
Authors: Venkatalakshmi Jakka | Anandarup Goswami | Anil Kumar Nallajarla | Uttariya Roy | Koigoora Srika | Shubhalakshmi Sengupta
Source: Research Square (preprint, 2023-05-18)
Field: Materials Science — Biomaterials

Coconut Coir derived Nanocellulose as an Efficient Adsorbent for Removal of Cationic Dye Safranine -O: A detailed Mechanistic Adsorption Study Adsorption ; Thermogravimetric analysis ; Nanocellulose ; Coir ; Materials science ; Langmuir adsorption model ; Chemical engineering ; Nuclear chemistry ; Fourier transform infrared spectroscopy ; Scanning electron microscope ; Thermal stability ; Chemistry ; Cellulose ; Organic chemistry ; Composite material Advanced Cellulose Research Studies ; Adsorption and biosorption for pollutant removal ; Membrane Separation Technologies
Authors: L. A. Savintseva | Alexander Avdoshin | Stanislav K. Ignatov | Alexander S. Novikov
Source: International Journal of Molecular Sciences (article, 2023-01-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Theoretical Study of Charge Mobility in Crystal Porphine and a Computer Design of a Porphine-Based Semiconductive Discotic Liquid Mesophase Organic semiconductors are the focus of numerous studies; they are used in electronic devices. Modern research involves the production of neuromorphic organic materials, including those based on liquid crystal materials. The purpose of this work involves the theoretical modeling of molecules (the "core with branches" type) to construct a discotic mesophase capable of performing the functions of a neuromorphic material. For this purpose, the conductivity of crystal porphine, which can act as the nucleus of a molecule of the "core with branches" type, was investigated. The Marcus theory charge mobility values for the hole and electron were 0.148 and 0.088 cm<sup>2</sup>/V·s, respectively (the MOO method for calculating transfer integrals), and 0.561 and 0.160 cm<sup>2</sup>/V·s (DIPRO method). Based on TD-HF (HF-3c level of theory) calculations, possible structures of molecules for the formation of a discotic mesophase are proposed. Mesophase ; Discotic liquid crystal ; Charge (physics) ; Materials science ; Liquid crystal ; Crystallography ; Optoelectronics ; Chemistry ; Physics Liquid Crystal Research Advancements ; Organic Electronics and Photovoltaics ; Lipid Membrane Structure and Behavior
Authors: Milena Latz | Alexander Böhme | Nadin Ulrich
Source: Scientific Reports (article, 2023-12-20)
Field: Chemistry — Spectroscopy

Reactivity-based identification of oxygen containing functional groups of chemicals applied as potential classifier in non-target analysis In this work, we developed a reactivity-based strategy to identify functional groups of unknown analytes, which can be applied as classifier in non-target analysis with gas chromatography. The aim of this strategy is to reduce the number of potential candidate structures generated for a molecular formula determined by high resolution mass spectrometry. We selected an example of 18 isomers with the molecular formula C<sub>12</sub>H<sub>10</sub>O<sub>2</sub> to test the performance of different derivatization reagents, whereas our aim was to select mild and fast reaction conditions. Based on the results for the isomers, we developed a four-step workflow for the identification of functional groups containing oxygen. Derivatization ; Mass spectrometry ; Analyte ; Classifier (UML) ; Chemistry ; Reactivity (psychology) ; Reagent ; High resolution ; Chromatography ; Combinatorial chemistry ; Computer science ; Artificial intelligence ; Organic chemistry Analytical Chemistry and Chromatography ; Advanced Chemical Sensor Technologies ; Metabolomics and Mass Spectrometry Studies
Authors: Emma King‐Smith | Simon Berritt | Louise Bernier | Xinjun Hou | Jacquelyn Klug‐McLeod | Jason Mustakis | Neal W. Sach | Joseph W. Tucker | Qingyi Yang | Roger M. Howard | Alpha A. Lee
Source: ChemRxiv (preprint, 2023-09-05)
Field: Materials Science — Materials Chemistry

Probing the Chemical "Reactome" with High Throughput Experimentation Data High-throughput experimentation (HTE) has the potential to improve our understanding of organic chemistry by systematically interrogating reactivity across diverse chemical spaces. Notable bottlenecks include few publicly available large-scale datasets and the need for facile interpretation of these data's hidden chemical insights. Herein we report the development of a High Throughput Experimentation Analyzer (HiTEA), a robust and statistically rigorous framework which is applicable to any HTE dataset regardless of size, scope, or target reaction outcome. We improve the HTE data landscape with the disclosure of 39,000+ previously proprietary HTE reactions. HiTEA is validated on this dataset, showcasing the elucidation of hidden relationships between reaction components and outcomes as well as highlighting reaction space that necessitates further investigation. Scope (computer science) ; Throughput ; Computer science ; Chemical space ; Data science ; Interpretation (philosophy) ; Outcome (game theory) ; Key (lock) ; Chemistry ; Drug discovery ; Computer security Machine Learning in Materials Science ; Computational Drug Discovery Methods ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Andreas Röckert | Jolla Kullgren | Daniel Sethio | Lorenzo Agosta | Kersti Hermansson
Source: The Journal of Chemical Physics (article, 2023-07-25)
Field: Materials Science — Materials Chemistry

Water on ceria{111}: Comparison between 23 experimental vibrational studies in the literature and new modeling Theoretical and experimental vibrational signatures of H2O and OH- (dissociated water) adsorbed on stoichiometric ceria{111} surfaces are compared. The experimental ones were collected from low-coverage experiments in the literature, and the theoretical anharmonic frequencies were generated using density functional theory calculations employing the optPBE-vdW functional for coverages from 0.5 to a few monolayers. It is found that (i) the experiments and our calculations overall agree well, lending credibility to both; (ii) the calculations manage to resolve the large class of H-bonded motifs into frequency classes that can guide experimental assignments; (iii) it is possible to find a geometrical H-bond definition that also captures the OH vibrational frequency downshifts well: R(H⋯O) ≤2.5 Å and the O-H⋯O angle θ ≥ 100°; and (iv) the frequency vs electric field relations for water and hydroxides (i.e., dissociated water) follow different and well-separated curves. Anharmonicity ; Density functional theory ; Stoichiometry ; Monolayer ; Chemistry ; Molecular vibration ; Materials science ; Computational chemistry ; Molecular physics ; Physical chemistry ; Physics ; Molecule ; Condensed matter physics ; Nanotechnology Catalytic Processes in Materials Science ; Advanced Condensed Matter Physics ; Electronic and Structural Properties of Oxides
Authors: Alberto Boscá | Antonio Ladrón-de-Guevara | Jorge Pedrós | Javier Martı́nez | Rajveer Fandan | F. Calle
Source: Crystal Growth & Design (article, 2023-08-16)
Field: Materials Science — Materials Chemistry

Parameter Space for Chemical Vapor Deposition Graphene in Cold-Wall Reactors under High Precursor Flow Rate Nowadays, promising proof-of-concept graphene technologies already exist, although converting them into a commercial success requires a high-throughput fabrication process providing a high-quality material. Chemical vapor deposition (CVD) has proven to be the enabling technology for this purpose. However, as typical CVD systems are based on laboratory-scale tubular hot-wall reactors, a comprehensive study is required to translate the optimal thermodynamic configuration into industry-ready CVD cold-wall reactors, capable of increasing the growth area and the process efficiency and yield, hence drastically reducing the costs. In this work, a study on how the thermodynamic parameters affect the growth dynamics and the material quality in a cold-wall reactor under high precursor flow rate is presented. The growth dynamics have been assessed in terms of the lateral growth rate and the nucleation density by means of scanning electron microscopy and image-classification techniques, whereas the quality of the single crystals has been evaluated through Raman mapping and electrical measurements. The parameter space defined by the experimental data has been compared with the predictions based on free Gibbs energy minimization, obtaining an overall good qualitative agreement and proving the suitability of the high precursor flow rate regime for achieving a high-quality material at moderate growth times. Chemical vapor deposition ; Nucleation ; Graphene ; Materials science ; Yield (engineering) ; Volumetric flow rate ; Nanotechnology ; Process engineering ; Deposition (geology) ; Growth rate ; Chemistry ; Thermodynamics ; Composite material ; Mathematics Graphene research and applications ; Nanowire Synthesis and Applications ; Thermal properties of materials
Authors: Alessandra del Masto | Jean Baccou | G. Tréglia | Fabienne Ribeiro | Céline Varvenne
Source: Computational Materials Science (article, 2023-10-05)
Field: Materials Science — Materials Chemistry

Insights on the capabilities and improvement ability of classical many-body potentials: Application to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si325.svg" display="inline" id="d1e1751"><mml:mi>α</mml:mi></mml:math>-zirconium Flexibility (engineering) ; Sensitivity (control systems) ; Transferability ; Computer science ; Simple (philosophy) ; Moment (physics) ; Statistical physics ; Physics ; Machine learning ; Mathematics ; Quantum mechanics ; Statistics ; Electronic engineering ; Engineering Nuclear Materials and Properties ; Machine Learning in Materials Science ; Advanced Chemical Physics Studies
Authors: Karim Muratov | Emil Zaripov | Maxim V. Berezovski | Fabien Gagosz
Source: ChemRxiv (preprint, 2023-08-15)
Field: Chemistry — Organic Chemistry

DFT-guided Development of New Hemilabile (P^N) Ligands for Gold-(I/III) RedOx Catalysis : Application to the Thiotosylation of Aryl Iodides Ligand-enabled oxidative addition of Csp2-X bonds to Au(I) centers has recently appeared as a valuable strategy for the development of catalytic RedOx processes. Several cross-coupling reactions that were previously considered difficult to achieve were reported lately, thus expanding the synthetic potential of gold(I) complexes beyond the traditional nucleophilic functionalization of pi-systems. MeDalPhos has played an important role in this development and, despite several studies on alternative structures, remains so far, the only general ligand for such process. We report herein the discovery and the DFT-guided structural optimization of a new family of hemilabile (P^N) ligands that can promote oxidative addition of aryl iodides to gold(I). These flexible ligands, which possess a common 2-methylamino heteroaromatic N-donor motif, are structurally and electronically tunable, beyond being easily accessible and affordable. The corresponding Au(I) complexes were shown to outperform the reactivity of (MeDalPhos)Au(I) in a series of alkoxy- and amidoarylation of alkenes. Their synthetic potential and comparatively higher reactivity were further highlighted in the thiotosylation of aryl iodides, a challenging unreported C-S cross-coupling reaction that could not be achieved under classical Pd(0/II) catalysis and that allows a general and divergent access to aryl sulfur derivatives. Nucleophile ; Aryl ; Chemistry ; Reactivity (psychology) ; Catalysis ; Combinatorial chemistry ; Ligand (biochemistry) ; Redox ; Alkoxy group ; Nucleophilic addition ; Reductive elimination ; Coupling reaction ; Stereochemistry ; Organic chemistry ; Receptor Sulfur-Based Synthesis Techniques ; Catalytic C–H Functionalization Methods ; Catalytic Alkyne Reactions
Authors: Joseph Severino | Hyun I. Kim | Geena L. Ferrelli | Rafael J. Zaldivar
Source: Polymer Composites (article, 2023-08-16)
Field: Materials Science — Materials Chemistry

Degradation of <scp>high‐performance</scp> cyanate ester space composites by anodized aluminum Abstract Cyanate esters are preferred resins for space composites based on excellent mechanical, thermal and dimensional properties. Yet, they are sensitive to co‐reactions with secondary constituents making compatibility a processing challenge. Anodized aluminum mandrels are commonly used for composite manufacturing but deleterious interactions with cyanate ester is not well understood. We investigate here the interaction of anodized aluminum mandrels with surrounding environments and its impact on cure, thermal stability and mechanical properties of M55J/RS3C composites. The uptake and diffusivity of environmental moisture in mandrels was determined gravimetrically and fit to a predictive Fickian model. Cured composite properties were evaluated and correlated with glass transition temperatures (Tg) by dynamic mechanical analysis (DMA), thermal stability by thermal gravimetric analysis (TGA), mechanical properties by flatwise tensile test, and the degradation depth profile by atomic force microscopy (AFM). Parallel to previous results for RS3C but more severe, the degradation penetrated up to 500 μm with reductions of 90°C in Tg, 100°C in thermal stability and 33% mass loss. The inorganic oxide surprisingly absorbs 10× more water at 10× higher rate than composite mandrel materials. The reported results show the anodization presents a unique hydrolysis risk when manufacturing cyanate ester composites so disciplined use and environmental conditioning should be considered when developing space structures. Highlights Cyanate ester composites degraded by anodized mandrels for all conditions. Thermogram signals correlate to composite mechanical degradation. Composite degradation depth gradient determined by atomic force microscopy. Cyanate ester ; Materials science ; Composite material ; Composite number ; Thermal stability ; Thermogravimetric analysis ; Dynamic mechanical analysis ; Anodizing ; Ultimate tensile strength ; Aluminium ; Polymer ; Chemical engineering ; Epoxy Anodic Oxide Films and Nanostructures ; Advanced ceramic materials synthesis ; Smart Materials for Construction
Authors: Christoph Ortner
Source: arXiv (Cornell University) (preprint, 2023-08-08)
Field: Materials Science — Materials Chemistry

On the Atomic Cluster Expansion: interatomic potentials and beyond KIM REVIEW, Volume 1, Article 01, 2023 Invariant (physics) ; Cluster (spacecraft) ; Translation (biology) ; Atom (system on chip) ; Interatomic potential ; Cluster expansion ; Permutation (music) ; Atomic physics ; Physics ; Chemistry ; Quantum mechanics ; Computer science ; Molecular dynamics ; Gene Machine Learning in Materials Science ; Inorganic Chemistry and Materials ; Advanced Chemical Physics Studies
Authors: D. V. Khakhar
Source: International Journal for Research in Applied Science and Engineering Technology (article, 2023-07-08)
Field: Chemistry — Physical and Theoretical Chemistry

Quantum Mechanics for Materials Science: Understanding the Atomic Scale Abstract: Quantum mechanics has transformed materials research by offering a fundamental insight of matter's behaviour at the atomic and subatomic scales. The purpose of this research study is to investigate the applications of quantum mechanics in materials science, with a focus on the insights it provides into the properties and behaviour of materials. We look at core quantum mechanics ideas such wave-particle duality, the Schrödinger equation, and quantum states and examine how these apply to materials science. In addition, we look at specific areas where quantum mechanics is important, such as electronic structure calculations, band theory, and quantum confinement effects. This paper emphasises quantum mechanics' interdisciplinary character and its tremendous impact on increasing our understanding of materials, enabling the design and discovery of novel materials. Subatomic particle ; Quantum mechanics ; Physics ; Quantum ; Quantum information science ; Elementary particle Advanced Physical and Chemical Molecular Interactions ; Chemical and Physical Properties of Materials
Authors: Samuel H. Newman-Stonebraker | T. Judah Raab | Hootan Roshandel | Abigail G. Doyle
Source: ChemRxiv (preprint, 2023-06-15)
Field: Chemistry — Organic Chemistry

Synthesis of Nickel(I)–Bromide Complexes via Oxidation and Ligand Displacement: Evaluation of Ligand Effects on Speciation and Reactivity Nickel’s +1 oxidation state has received much interest due to its varied and often enigmatic behavior in increasingly popular catalytic methods. In part, the lack of understanding about Ni(I) results from common synthetic strategies limiting the breadth of complexes that are accessible for mechanistic study and catalyst design. We report an oxidative approach using tribromide salts that allows for the generation of a well-defined precursor, [Ni(I)(COD)Br]2, as well as several new NiI complexes. Included among them are complexes bearing bulky monophosphines, for which structure–speciation relationships are established and catalytic reactivity in a Suzuki-Miyaura coupling (SMC) is investigated. Notably, these routes also allow for the synthesis of well-defined monomeric t-Bu-bpy-bound Ni(I) complexes, which has not previously been achieved. These complexes, which react with aryl halides, can enable previously challenging mechanistic investigations and present new opportunities for catalysis and synthesis. Nickel ; Reactivity (psychology) ; Catalysis ; Bromide ; Ligand (biochemistry) ; Chemistry ; Oxidative addition ; Halide ; Aryl ; Combinatorial chemistry ; Oxidation state ; Organic chemistry Catalytic Cross-Coupling Reactions ; Catalytic C–H Functionalization Methods ; Asymmetric Hydrogenation and Catalysis
Authors: Raheel Ahmed Janjua | Wenbin Ji | Nayyar Abbas Shah | Julian Evans | Ruili Zhang | Sheng Zhang | Sailing He
Source: Progress In Electromagnetics Research M (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Advances in Synthesis Strategies for Lanthanide-based NaYF4 Upconversion Nanocrystals and Their Applications in Ratiometric Thermometry The optical characteristics and varied applications of lanthanide-doped NaYF4 upconversion nanocrystals have received considerable interest in recent years, such as in ratiometric thermometry. This review thoroughly examines the various synthesis processes utilized in producing these nanocrystals and their application in temperature sensing. Synthesis of NaYF4 upconversion nanocrystals is a complex procedure that requires careful management of dopant concentrations, crystal phase, size, and shape. The distinctive luminescent characteristics of lanthanide ions, which facilitate the transformation of photons with low energy into emissions with higher energy, render NaYF4 nanocrystals suitable for ratiometric thermometry applications. We explore the fundamental concepts underlying upconversion luminescence in developing ratiometric temperature sensors. In this discourse, we examine the selection of lanthanide dopants, the mechanics underlying their energy transmission, and the development of customized sensor architectures. This review covers the recent progress and utilization of NaYF4 upconversion nanocrystals in ratiometric thermometry, including diverse areas such as biological temperature detection, environmental surveillance, and materials research. We evaluate the obstacles and potential advancements in this domain, specifically emphasizing approaches to improving temperature sensors' precision, responsiveness, and applicability based on upconversion. Photon upconversion ; Lanthanide ; Nanocrystal ; Materials science ; Nanotechnology ; Optoelectronics ; Chemistry ; Luminescence ; Ion ; Organic chemistry Luminescence Properties of Advanced Materials ; Optical properties and cooling technologies in crystalline materials ; Inorganic Fluorides and Related Compounds