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2007-09-13 00:00:00
2025-05-15 00:00:00
Franz Damma{\ss}, Karl A. Kalina, Markus K\"astner
When invariants matter: The role of I1 and I2 in neural network models of incompressible hyperelasticity
null
null
null
cond-mat.mtrl-sci cond-mat.soft
For the formulation of machine learning-based material models, the usage of invariants of deformation tensors is attractive, since this can a priori guarantee objectivity and material symmetry. In this work, we consider incompressible, isotropic hyperelasticity, where two invariants I1 and I2 are required for depicting a deformation state. First, we aim at enhancing the understanding of the invariants. We provide an explicit representation of the set of invariants that are admissible, i.e. for which (I1, I2) a deformation state does indeed exist. Furthermore, we prove that uniaxial and equi-biaxial deformation correspond to the boundary of the set of admissible invariants. Second, we study how the experimentally-observed behaviour of different materials can be captured by means of neural network models of incompressible hyperelasticity, depending on whether both I1 and I2 or solely one of the invariants, i.e. either only I1 or only I2, are taken into account. To this end, we investigate three different experimental data sets from the literature. In particular, we demonstrate that considering only one invariant, either I1 or I2, can allow for good agreement with experiments in case of small deformations. In contrast, it is necessary to consider both invariants for precise models at large strains, for instance when rubbery polymers are deformed. Moreover, we show that multiaxial experiments are strictly required for the parameterisation of models considering I2. Otherwise, if only data from uniaxial deformation is available, significantly overly stiff responses could be predicted for general deformation states. On the contrary, I1-only models can make qualitatively correct predictions for multiaxial loadings even if parameterised only from uniaxial data, whereas I2-only models are completely incapable in even qualitatively capturing experimental stress data at large deformations.
[{'version': 'v1', 'created': 'Wed, 26 Mar 2025 14:43:11 GMT'}]
2025-03-27
Takuya Shibayama, Hideaki Imamura, Katsuhiko Nishimra, Kohei Shinohara, Chikashi Shinagawa, So Takamoto, Ju Li
Efficient Crystal Structure Prediction Using Genetic Algorithm and Universal Neural Network Potential
null
null
null
cond-mat.mtrl-sci physics.comp-ph
Crystal structure prediction (CSP) is crucial for identifying stable crystal structures in given systems and is a prerequisite for computational atomistic simulations. Recent advances in neural network potentials (NNPs) have reduced the computational cost of CSP. However, searching for stable crystal structures across the entire composition space in multicomponent systems remains a significant challenge. Here, we propose a novel genetic algorithm (GA) -based CSP method using a universal NNP. Our GA-based methods are designed to efficiently expand convex hull volumes while preserving the diversity of crystal structures. This approach draws inspiration from the similarity between convex hull updates and Pareto front evolution in multi-objective optimization. Our evaluation shows that the present method outperforms the symmetry-aware random structure generation, achieving a larger convex hull with fewer trials. We demonstrated that our approach, combined with the developed universal NNP (PFP), can accurately reproduce and explore phase diagrams obtained through DFT calculations; this indicates the validity of PFP across a wide range of crystal structures and element combinations. This study, which integrates a universal NNP with a GA-based CSP method, highlights the promise of these methods in materials discovery.
[{'version': 'v1', 'created': 'Thu, 27 Mar 2025 06:38:59 GMT'}]
2025-03-28
Somayeh Hosseinhashemi, Philipp Rieder, Orkun Furat, Benedikt Prifling, Changlin Wu, Christoph Thon, Volker Schmidt, Carsten Schilde
Statistical learning of structure-property relationships for transport in porous media, using hybrid AI modeling
null
null
null
cond-mat.mtrl-sci cs.LG
The 3D microstructure of porous media, such as electrodes in lithium-ion batteries or fiber-based materials, significantly impacts the resulting macroscopic properties, including effective diffusivity or permeability. Consequently, quantitative structure-property relationships, which link structural descriptors of 3D microstructures such as porosity or geodesic tortuosity to effective transport properties, are crucial for further optimizing the performance of porous media. To overcome the limitations of 3D imaging, parametric stochastic 3D microstructure modeling is a powerful tool to generate many virtual but realistic structures at the cost of computer simulations. The present paper uses 90,000 virtually generated 3D microstructures of porous media derived from literature by systematically varying parameters of stochastic 3D microstructure models. Previously, this data set has been used to establish quantitative microstructure-property relationships. The present paper extends these findings by applying a hybrid AI framework to this data set. More precisely, symbolic regression, powered by deep neural networks, genetic algorithms, and graph attention networks, is used to derive precise and robust analytical equations. These equations model the relationships between structural descriptors and effective transport properties without requiring manual specification of the underlying functional relationship. By integrating AI with traditional computational methods, the hybrid AI framework not only generates predictive equations but also enhances conventional modeling approaches by capturing relationships influenced by specific microstructural features traditionally underrepresented. Thus, this paper significantly advances the predictive modeling capabilities in materials science, offering vital insights for designing and optimizing new materials with tailored transport properties.
[{'version': 'v1', 'created': 'Thu, 27 Mar 2025 14:46:40 GMT'}]
2025-03-31
Izumi Takahara, Teruyasu Mizoguchi and Bang Liu
Accelerated Inorganic Materials Design with Generative AI Agents
null
null
null
cond-mat.mtrl-sci
Designing inorganic crystalline materials with tailored properties is critical to technological innovation, yet current generative computational methods often struggle to efficiently explore desired targets with sufficient interpretability. Here, we present MatAgent, a generative approach for inorganic materials discovery that harnesses the powerful reasoning capabilities of large language models (LLMs). By combining a diffusion-based generative model for crystal structure estimation with a predictive model for property evaluation, MatAgent uses iterative, feedback-driven guidance to steer material exploration precisely toward user-defined targets. Integrated with external cognitive tools-including short-term memory, long-term memory, the periodic table, and a comprehensive materials knowledge base-MatAgent emulates human expert reasoning to vastly expand the accessible compositional space. Our results demonstrate that MatAgent robustly directs exploration toward desired properties while consistently achieving high compositional validity, uniqueness, and material novelty. This framework thus provides a highly interpretable, practical, and versatile AI-driven solution to accelerate the discovery and design of next-generation inorganic materials.
[{'version': 'v1', 'created': 'Tue, 1 Apr 2025 12:51:07 GMT'}]
2025-04-02
Zhendong Cao, Lei Wang
CrystalFormer-RL: Reinforcement Fine-Tuning for Materials Design
null
null
null
cond-mat.mtrl-sci cs.LG physics.comp-ph
Reinforcement fine-tuning has instrumental enhanced the instruction-following and reasoning abilities of large language models. In this work, we explore the applications of reinforcement fine-tuning to the autoregressive transformer-based materials generative model CrystalFormer (arXiv:2403.15734) using discriminative machine learning models such as interatomic potentials and property prediction models. By optimizing reward signals-such as energy above the convex hull and material property figures of merit-reinforcement fine-tuning infuses knowledge from discriminative models into generative models. The resulting model, CrystalFormer-RL, shows enhanced stability in generated crystals and successfully discovers crystals with desirable yet conflicting material properties, such as substantial dielectric constant and band gap simultaneously. Notably, we observe that reinforcement fine-tuning enables not only the property-guided novel material design ability of generative pre-trained model but also unlocks property-driven material retrieval from the unsupervised pre-training dataset. Leveraging rewards from discriminative models to fine-tune materials generative models opens an exciting gateway to the synergies of the machine learning ecosystem for materials.
[{'version': 'v1', 'created': 'Thu, 3 Apr 2025 07:59:30 GMT'}]
2025-04-04
Yuta Yahagi, Kiichi Obuchi, Fumihiko Kosaka, Kota Matsui
Transfer learning from first-principles calculations to experiments with chemistry-informed domain transformation
null
null
null
physics.chem-ph cond-mat.mtrl-sci cs.LG physics.comp-ph
Simulation-to-Real (Sim2Real) transfer learning, the machine learning technique that efficiently solves a real-world task by leveraging knowledge from computational data, has received increasing attention in materials science as a promising solution to the scarcity of experimental data. We proposed an efficient transfer learning scheme from first-principles calculations to experiments based on the chemistry-informed domain transformation, that integrates the heterogeneous source and target domains by harnessing the underlying physics and chemistry. The proposed method maps the computational data from the simulation space (source domain) into the space of experimental data (target domain). During this process, these qualitatively different domains are efficiently integrated by a couple of prior knowledge of chemistry, (1) the statistical ensemble, and (2) the relationship between source and target quantities. As a proof-of-concept, we predict the catalyst activity for the reverse water-gas shift reaction by using the abundant first-principles data in addition to the experimental data. Through the demonstration, we confirmed that the transfer learning model exhibits positive transfer in accuracy and data efficiency. In particular, a significantly high accuracy was achieved despite using a few (less than ten) target data in domain transformation, whose accuracy is one order of magnitude smaller than that of a full scratch model trained with over 100 target data. This result indicates that the proposed method leverages the high prediction performance with few target data, which helps to save the number of trials in real laboratories.
[{'version': 'v1', 'created': 'Thu, 20 Mar 2025 15:14:23 GMT'}, {'version': 'v2', 'created': 'Mon, 7 Apr 2025 07:29:31 GMT'}]
2025-04-08
Lingyu Kong, Nima Shoghi, Guoxiang Hu, Pan Li, Victor Fung
MatterTune: An Integrated, User-Friendly Platform for Fine-Tuning Atomistic Foundation Models to Accelerate Materials Simulation and Discovery
null
null
null
cond-mat.mtrl-sci cs.AI cs.LG
Geometric machine learning models such as graph neural networks have achieved remarkable success in recent years in chemical and materials science research for applications such as high-throughput virtual screening and atomistic simulations. The success of these models can be attributed to their ability to effectively learn latent representations of atomic structures directly from the training data. Conversely, this also results in high data requirements for these models, hindering their application to problems which are data sparse which are common in this domain. To address this limitation, there is a growing development in the area of pre-trained machine learning models which have learned general, fundamental, geometric relationships in atomistic data, and which can then be fine-tuned to much smaller application-specific datasets. In particular, models which are pre-trained on diverse, large-scale atomistic datasets have shown impressive generalizability and flexibility to downstream applications, and are increasingly referred to as atomistic foundation models. To leverage the untapped potential of these foundation models, we introduce MatterTune, a modular and extensible framework that provides advanced fine-tuning capabilities and seamless integration of atomistic foundation models into downstream materials informatics and simulation workflows, thereby lowering the barriers to adoption and facilitating diverse applications in materials science. In its current state, MatterTune supports a number of state-of-the-art foundation models such as ORB, MatterSim, JMP, and EquformerV2, and hosts a wide range of features including a modular and flexible design, distributed and customizable fine-tuning, broad support for downstream informatics tasks, and more.
[{'version': 'v1', 'created': 'Mon, 14 Apr 2025 19:12:43 GMT'}]
2025-04-16
Yahao Dai, Henry Chan, Aikaterini Vriza, Fredrick Kim, Yunfei Wang, Wei Liu, Naisong Shan, Jing Xu, Max Weires, Yukun Wu, Zhiqiang Cao, C. Suzanne Miller, Ralu Divan, Xiaodan Gu, Chenhui Zhu, Sihong Wang, Jie Xu
Adaptive AI decision interface for autonomous electronic material discovery
null
null
null
cond-mat.mtrl-sci cs.AI
AI-powered autonomous experimentation (AI/AE) can accelerate materials discovery but its effectiveness for electronic materials is hindered by data scarcity from lengthy and complex design-fabricate-test-analyze cycles. Unlike experienced human scientists, even advanced AI algorithms in AI/AE lack the adaptability to make informative real-time decisions with limited datasets. Here, we address this challenge by developing and implementing an AI decision interface on our AI/AE system. The central element of the interface is an AI advisor that performs real-time progress monitoring, data analysis, and interactive human-AI collaboration for actively adapting to experiments in different stages and types. We applied this platform to an emerging type of electronic materials-mixed ion-electron conducting polymers (MIECPs) -- to engineer and study the relationships between multiscale morphology and properties. Using organic electrochemical transistors (OECT) as the testing-bed device for evaluating the mixed-conducting figure-of-merit -- the product of charge-carrier mobility and the volumetric capacitance ({\mu}C*), our adaptive AI/AE platform achieved a 150% increase in {\mu}C* compared to the commonly used spin-coating method, reaching 1,275 F cm-1 V-1 s-1 in just 64 autonomous experimental trials. A study of 10 statistically selected samples identifies two key structural factors for achieving higher volumetric capacitance: larger crystalline lamellar spacing and higher specific surface area, while also uncovering a new polymer polymorph in this material.
[{'version': 'v1', 'created': 'Thu, 17 Apr 2025 21:26:48 GMT'}]
2025-04-21
Theo Jaffrelot Inizan, Sherry Yang, Aaron Kaplan, Yen-hsu Lin, Jian Yin, Saber Mirzaei, Mona Abdelgaid, Ali H. Alawadhi, KwangHwan Cho, Zhiling Zheng, Ekin Dogus Cubuk, Christian Borgs, Jennifer T. Chayes, Kristin A. Persson, Omar M. Yaghi
System of Agentic AI for the Discovery of Metal-Organic Frameworks
null
null
null
cond-mat.mtrl-sci cs.AI cs.CL cs.MA
Generative models and machine learning promise accelerated material discovery in MOFs for CO2 capture and water harvesting but face significant challenges navigating vast chemical spaces while ensuring synthetizability. Here, we present MOFGen, a system of Agentic AI comprising interconnected agents: a large language model that proposes novel MOF compositions, a diffusion model that generates crystal structures, quantum mechanical agents that optimize and filter candidates, and synthetic-feasibility agents guided by expert rules and machine learning. Trained on all experimentally reported MOFs and computational databases, MOFGen generated hundreds of thousands of novel MOF structures and synthesizable organic linkers. Our methodology was validated through high-throughput experiments and the successful synthesis of five "AI-dreamt" MOFs, representing a major step toward automated synthesizable material discovery.
[{'version': 'v1', 'created': 'Fri, 18 Apr 2025 23:54:25 GMT'}]
2025-04-22
Ahmed Sobhi Saleh, Kristof Croes, Hajdin Ceric, Ingrid De Wolf, Houman Zahedmanesh
Novel Concept-Oriented Synthetic Data approach for Training Generative AI-Driven Crystal Grain Analysis Using Diffusion Model
Computational Materials Science, Vol 251 (2025)
10.1016/j.commatsci.2025.113723
null
cs.LG cond-mat.mtrl-sci
The traditional techniques for extracting polycrystalline grain structures from microscopy images, such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM), are labour-intensive, subjective, and time-consuming, limiting their scalability for high-throughput analysis. In this study, we present an automated methodology integrating edge detection with generative diffusion models to effectively identify grains, eliminate noise, and connect broken segments in alignment with predicted grain boundaries. Due to the limited availability of adequate images preventing the training of deep machine learning models, a new seven-stage methodology is employed to generate synthetic TEM images for training. This concept-oriented synthetic data approach can be extended to any field of interest where the scarcity of data is a challenge. The presented model was applied to various metals with average grain sizes down to the nanoscale, producing grain morphologies from low-resolution TEM images that are comparable to those obtained from advanced and demanding experimental techniques with an average accuracy of 97.23%.
[{'version': 'v1', 'created': 'Mon, 21 Apr 2025 00:46:28 GMT'}]
2025-04-22
Clement Vincely, Amin Reiners-Sakic, Vedant Dave, Erwin Povoden-Karadeniz, Elmar Rueckert, Ronald Schnitzer, David Holec
Amending CALPHAD databases using a neural network for predicting mixing enthalpy of liquids
null
null
null
physics.chem-ph cond-mat.dis-nn cond-mat.mtrl-sci
In order to establish the thermodynamic stability of a system, knowledge of its Gibbs free energy is essential. Most often, the Gibbs free energy is predicted within the CALPHAD framework using models employing thermodynamic properties, such as the mixing enthalpy, heat capacity, and activity coefficients. Here, we present a deep-learning approach capable of predicting the mixing enthalpy of liquid phases of binary systems that were not present in the training dataset. Therefore, our model allows for a system-informed enhancement of the thermodynamic description to unknown binary systems based on information present in the available thermodynamic assessment. Thereby, significant experimental efforts in assessing new systems can be spared. We use an open database for steels containing 91 binary systems to generate our initial training (and validation) and amend it with several direct experimental reports. The model is thoroughly tested using different strategies, including a test of its predictive capabilities. The model shows excellent predictive capabilities outside of the training dataset as soon as some data containing species of the predicted system is included in the training dataset. The estimated uncertainty of the model is below 1 kJ/mol for the predicted mixing enthalpy. Subsequently, we used our model to predict the enthalpy of mixing of all binary systems not present in the original database and extracted the Redlich-Kister parameters, which can be readily reintegrated into the thermodynamic database file.
[{'version': 'v1', 'created': 'Fri, 25 Apr 2025 14:08:28 GMT'}, {'version': 'v2', 'created': 'Mon, 28 Apr 2025 05:44:02 GMT'}]
2025-04-29
Zuhong Lin, Daoyuan Ren, Kai Ran, Sun Jing, Xiaotiang Huang, Haiyang He, Pengxu Pan, Xiaohang Zhang, Ying Fang, Tianying Wang, Minli Wu, Zhanglin Li, Xiaochuan Zhang, Haipu Li, Jingjing Yao
Reshaping MOFs Text Mining with a Dynamic Multi-Agent Framework of Large Language Agents
null
null
null
cs.AI cond-mat.mtrl-sci
The mining of synthesis conditions for metal-organic frameworks (MOFs) is a significant focus in materials science. However, identifying the precise synthesis conditions for specific MOFs within the vast array of possibilities presents a considerable challenge. Large Language Models (LLMs) offer a promising solution to this problem. We leveraged the capabilities of LLMs, specifically gpt-4o-mini, as core agents to integrate various MOF-related agents, including synthesis, attribute, and chemical information agents. This integration culminated in the development of MOFh6, an LLM tool designed to streamline the MOF synthesis process. MOFh6 allows users to query in multiple formats, such as submitting scientific literature, or inquiring about specific MOF codes or structural properties. The tool analyzes these queries to provide optimal synthesis conditions and generates model files for density functional theory pre modeling. We believe MOFh6 will enhance efficiency in the MOF synthesis of all researchers.
[{'version': 'v1', 'created': 'Sat, 26 Apr 2025 09:55:04 GMT'}]
2025-04-29
Yomn Alkabakibi, Congwei Xie, Artem R. Oganov
Graph Neural Network Prediction of Nonlinear Optical Properties
null
null
null
cond-mat.mtrl-sci cs.LG physics.optics
Nonlinear optical (NLO) materials for generating lasers via second harmonic generation (SHG) are highly sought in today's technology. However, discovering novel materials with considerable SHG is challenging due to the time-consuming and costly nature of both experimental methods and first-principles calculations. In this study, we present a deep learning approach using the Atomistic Line Graph Neural Network (ALIGNN) to predict NLO properties. Sourcing data from the Novel Opto-Electronic Materials Discovery (NOEMD) database and using the Kurtz-Perry (KP) coefficient as the key target, we developed a robust model capable of accurately estimating nonlinear optical responses. Our results demonstrate that the model achieves 82.5% accuracy at a tolerated absolute error up to 1 pm/V and relative error not exceeding 0.5. This work highlights the potential of deep learning in accelerating the discovery and design of advanced optical materials with desired properties.
[{'version': 'v1', 'created': 'Mon, 28 Apr 2025 17:03:22 GMT'}]
2025-04-29
Ivan Pinto-Huguet, Marc Botifoll, Xuli Chen, Martin Borstad Eriksen, Jing Yu, Giovanni Isella, Andreu Cabot, Gonzalo Merino, Jordi Arbiol
Enhancing atomic-resolution in electron microscopy: A frequency-domain deep learning denoiser
null
null
null
cond-mat.mtrl-sci
Atomic resolution electron microscopy, particularly high-angle annular dark-field scanning transmission electron microscopy, has become an essential tool for many scientific fields, when direct visualization of atomic arrangements and defects are needed, as they dictate the material's functional and mechanical behavior. However, achieving this precision is often hindered by noise, arising from electron microscopy acquisition limitations, particularly when imaging beam-sensitive materials or light atoms. In this work, we present a deep learning-based denoising approach that operates in the frequency domain using a convolutional neural network U-Net trained on simulated data. To generate the training dataset, we simulate FFT patterns for various materials, crystallographic orientations, and imaging conditions, introducing noise and drift artifacts to accurately mimic experimental scenarios. The model is trained to identify relevant frequency components, which are then used to enhance experimental images by applying element-wise multiplication in the frequency domain. The model enhances experimental images by identifying and amplifying relevant frequency components, significantly improving signal-to-noise ratio while preserving structural integrity. Applied to both Ge quantum wells and WS2 monolayers, the method facilitates more accurate strain quantitative analyses, critical for assessing functional device performance (e.g. quantum properties in SiGe quantum wells), and enables the clear identification of light atoms in beam sensitive materials. Our results demonstrate the potential of automated frequency-based deep learning denoising as a useful tool for atomic-resolution nano-materials analysis.
[{'version': 'v1', 'created': 'Sat, 3 May 2025 11:31:53 GMT'}]
2025-05-06
Yoel Zimmermann, Adib Bazgir, Alexander Al-Feghali, Mehrad Ansari, L. Catherine Brinson, Yuan Chiang, Defne Circi, Min-Hsueh Chiu, Nathan Daelman, Matthew L. Evans, Abhijeet S. Gangan, Janine George, Hassan Harb, Ghazal Khalighinejad, Sartaaj Takrim Khan, Sascha Klawohn, Magdalena Lederbauer, Soroush Mahjoubi, Bernadette Mohr, Seyed Mohamad Moosavi, Aakash Naik, Aleyna Beste Ozhan, Dieter Plessers, Aritra Roy, Fabian Sch\"oppach, Philippe Schwaller, Carla Terboven, Katharina Ueltzen, Shang Zhu, Jan Janssen, Calvin Li, Ian Foster, and Ben Blaiszik
34 Examples of LLM Applications in Materials Science and Chemistry: Towards Automation, Assistants, Agents, and Accelerated Scientific Discovery
null
null
null
cs.LG cond-mat.mtrl-sci
Large Language Models (LLMs) are reshaping many aspects of materials science and chemistry research, enabling advances in molecular property prediction, materials design, scientific automation, knowledge extraction, and more. Recent developments demonstrate that the latest class of models are able to integrate structured and unstructured data, assist in hypothesis generation, and streamline research workflows. To explore the frontier of LLM capabilities across the research lifecycle, we review applications of LLMs through 34 total projects developed during the second annual Large Language Model Hackathon for Applications in Materials Science and Chemistry, a global hybrid event. These projects spanned seven key research areas: (1) molecular and material property prediction, (2) molecular and material design, (3) automation and novel interfaces, (4) scientific communication and education, (5) research data management and automation, (6) hypothesis generation and evaluation, and (7) knowledge extraction and reasoning from the scientific literature. Collectively, these applications illustrate how LLMs serve as versatile predictive models, platforms for rapid prototyping of domain-specific tools, and much more. In particular, improvements in both open source and proprietary LLM performance through the addition of reasoning, additional training data, and new techniques have expanded effectiveness, particularly in low-data environments and interdisciplinary research. As LLMs continue to improve, their integration into scientific workflows presents both new opportunities and new challenges, requiring ongoing exploration, continued refinement, and further research to address reliability, interpretability, and reproducibility.
[{'version': 'v1', 'created': 'Mon, 5 May 2025 22:08:37 GMT'}]
2025-05-07
Ting-Wei Hsu, Zhenyao Fang, Arun Bansil, and Qimin Yan
Accurate Prediction of Sequential Tensor Properties Using Equivariant Graph Neural Network
null
null
null
cond-mat.mtrl-sci physics.optics
Optical spectra serve as a powerful tool for probing the interactions between materials and light, unveiling complex electronic structures such as flat bands and nontrivial topological features. These insights are crucial for the development and optimization of photonic devices, including solar cells, light-emitting diodes, and photodetectors, where understanding the electronic structure directly impacts device performance. Moreover, in anisotropic bulk materials, the optical responses are direction-dependent, and predicting those response tensors still remains computationally demanding due to its inherent complexity and the constraint from crystal symmetry. To address this challenge, we introduce the sequential tensorial properties equivariant neural network (StepENN), a graph neural network architecture that maps crystal structures directly to their full optical tensors across different photon frequencies. By encoding the isotropic sequential scalar components and anisotropic sequential tensor components into l=0 and l=2 spherical tensor components, StepENN ensures symmetry-aware sequential tensor predictions that are consistent with the inherent symmetry constraints of crystal systems. Trained on a dataset of frequency-dependent permittivity tensors for 1,432 bulk semiconductors computed from first-principles methods, our model achieves a mean absolute error (MAE) of 24.216 millifarads per meter (mF/m) on the predicted tensorial spectra with 85.7% of its predictions exhibiting less than 10% relative error, demonstrating its potential for deriving other spectrum-related properties, such as optical conductivity. This framework opens new avenues for the data-driven design of materials with engineered anisotropic optical responses, accelerating material advances in optoelectronic applications.
[{'version': 'v1', 'created': 'Thu, 8 May 2025 00:10:41 GMT'}]
2025-05-09
Pungponhavoan Tep and Marc Bernacki
High-fidelity Grain Growth Modeling: Leveraging Deep Learning for Fast Computations
null
null
null
cond-mat.mtrl-sci cs.AI
Grain growth simulation is crucial for predicting metallic material microstructure evolution during annealing and resulting final mechanical properties, but traditional partial differential equation-based methods are computationally expensive, creating bottlenecks in materials design and manufacturing. In this work, we introduce a machine learning framework that combines a Convolutional Long Short-Term Memory networks with an Autoencoder to efficiently predict grain growth evolution. Our approach captures both spatial and temporal aspects of grain evolution while encoding high-dimensional grain structure data into a compact latent space for pattern learning, enhanced by a novel composite loss function combining Mean Squared Error, Structural Similarity Index Measurement, and Boundary Preservation to maintain structural integrity of grain boundary topology of the prediction. Results demonstrated that our machine learning approach accelerates grain growth prediction by up to \SI{89}{\times} faster, reducing computation time from \SI{10}{\minute} to approximately \SI{10}{\second} while maintaining high-fidelity predictions. The best model (S-30-30) achieving a structural similarity score of \SI{86.71}{\percent} and mean grain size error of just \SI{0.07}{\percent}. All models accurately captured grain boundary topology, morphology, and size distributions. This approach enables rapid microstructural prediction for applications where conventional simulations are prohibitively time-consuming, potentially accelerating innovation in materials science and manufacturing.
[{'version': 'v1', 'created': 'Thu, 8 May 2025 15:43:40 GMT'}]
2025-05-09
Jamie Holber and Krishna Garikipati
Equivariant graph neural network surrogates for predicting the properties of relaxed atomic configurations
null
null
null
cond-mat.mtrl-sci physics.comp-ph
Density functional theory (DFT) calculations determine the relaxed atomic positions and lattice parameters that minimize the formation energy of a structure. We present an equivariant graph neural network (EGNN) model to predict the outcome of DFT calculations for structures of interest. Cluster expansions are a well established approach for representing the formation energies. However, traditional cluster expansions are limited in their ability to handle variations from a fixed lattice, including interstitial atoms, amorphous materials, and materials with multiple structures. EGNNs offer a more flexible framework that inherently respects the symmetry of the system without being reliant on a particular lattice. In this work, we present the mathematical framework and the results of training for lithium cobalt oxide (LCO) at various compositions of lithium and arrangements of the lithium atoms. Our results demonstrate that the EGNN can accurately predict quantities outside the training set including the largest atomic displacements, the strain tensor and energy, and the formation energy providing greater insight into the system being studied without the need for more DFT calculations.
[{'version': 'v1', 'created': 'Mon, 12 May 2025 23:22:35 GMT'}]
2025-05-14
Purun-hanul Kim, Jeong Min Choi, Seungwu Han, Youngho Kang
Neural Network-Driven Molecular Insights into Alkaline Wet Etching of GaN: Toward Atomistic Precision in Nanostructure Fabrication
null
null
null
cond-mat.mtrl-sci
We present large-scale molecular dynamics (MD) simulations based on a machine-learning interatomic potential to investigate the wet etching behavior of various GaN facets in alkaline solution-a process critical to the fabrication of nitride-based semiconductor devices. A Behler-Parrinello-type neural network potential (NNP) was developed by training on extensive DFT datasets and iteratively refined to capture chemical reactions between GaN and KOH. To simulate the wet etching of GaN, we perform NNP-MD simulations using the temperature-accelerated dynamics approach, which accurately reproduces the experimentally observed structural modification of a GaN nanorod during alkaline etching. The etching simulations reveal surface-specific morphological evolutions: pyramidal etch pits emerge on the $-c$ plane, while truncated pyramidal pits form on the $+c$ surface. The non-polar m and a surfaces exhibit lateral etch progression, maintaining planar morphologies. Analysis of MD trajectories identifies key surface reactions governing the etching mechanisms. To gain deeper insights into the etching kinetics, we conduct enhanced-sampling MD simulations and construct free-energy profiles for Ga dissolution, a process that critically influences the overall etching rate. The $-c$, $a$, and $m$ planes exhibit moderate activation barriers, indicating the feasibility of alkaline wet etching. In contrast, the $+c$ surface displays a significantly higher barrier, illustrating its strong resistance to alkaline etching. Additionally, we show that Ga-O-Ga bridges can form on etched surfaces, potentially serving as carrier traps. By providing a detailed atomistic understanding of GaN wet etching, this work offers valuable guidance for surface engineering in GaN-based device fabrication.
[{'version': 'v1', 'created': 'Tue, 13 May 2025 02:01:07 GMT'}]
2025-05-14
Xinyu You, Xiang Liu, Chuan-Shen Hu, Kelin Xia and Tze Chien Sum
Quotient Complex Transformer (QCformer) for Perovskite Data Analysis
null
null
null
cs.LG cond-mat.mtrl-sci
The discovery of novel functional materials is crucial in addressing the challenges of sustainable energy generation and climate change. Hybrid organic-inorganic perovskites (HOIPs) have gained attention for their exceptional optoelectronic properties in photovoltaics. Recently, geometric deep learning, particularly graph neural networks (GNNs), has shown strong potential in predicting material properties and guiding material design. However, traditional GNNs often struggle to capture the periodic structures and higher-order interactions prevalent in such systems. To address these limitations, we propose a novel representation based on quotient complexes (QCs) and introduce the Quotient Complex Transformer (QCformer) for material property prediction. A material structure is modeled as a quotient complex, which encodes both pairwise and many-body interactions via simplices of varying dimensions and captures material periodicity through a quotient operation. Our model leverages higher-order features defined on simplices and processes them using a simplex-based Transformer module. We pretrain QCformer on benchmark datasets such as the Materials Project and JARVIS, and fine-tune it on HOIP datasets. The results show that QCformer outperforms state-of-the-art models in HOIP property prediction, demonstrating its effectiveness. The quotient complex representation and QCformer model together contribute a powerful new tool for predictive modeling of perovskite materials.
[{'version': 'v1', 'created': 'Wed, 14 May 2025 06:13:14 GMT'}]
2025-05-15