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Amorphous solids form an enormous and underutilized class of materials. In order to drive the discovery of new useful amorphous materials further we need to achieve a closer convergence between computational and experimental methods. In…

Disordered Systems and Neural Networks · Physics 2024-11-19 Ata Madanchi , Emna Azek , Karim Zongo , Laurent K. Béland , Normand Mousseau , Lena Simine

We investigate the structural and dynamical properties of binary aluminum-titanium liquid metallic alloys, as a function of temperature and composition. We make use of MD-simulations, using a transferable machine-learning potential…

We propose a novel active learning scheme for automatically sampling a minimum number of uncorrelated configurations for fitting the Gaussian Approximation Potential (GAP). Our active learning scheme consists of an unsupervised machine…

We have performed an approximate ab initio calculation of vibrational properties of hydrogenated amorphous silicon (a-Si:H) using a molecular dynamics method. A 216 atom model for pure amorphous silicon (a-Si) has been employed as a…

Disordered Systems and Neural Networks · Physics 2009-10-31 Serge M. Nakhmanson , D. A. Drabold

The anharmonic decay rates of atomic vibrations in amorphous silicon (a-Si) and paracrystalline silicon (p-Si), containing small crystalline grains embedded in a disordered matrix, are calculated using realistic structural models. The…

Disordered Systems and Neural Networks · Physics 2009-11-10 Jaroslav Fabian , Joseph L. Feldman , C. Stephen Hellberg , S. M. Nakhmanson

Accuracy of molecular dynamics simulations depends crucially on the interatomic potential used to generate forces. The gold standard would be first-principles quantum mechanics (QM) calculations, but these become prohibitively expensive at…

Amorphous materials are integral part of todays technology, they commonly are performant and versatile in integration. Consequently, future applications increasingly aim to harvest the potential of the amorphous state. Establishing its…

Silicon carbide (SiC) polymorphs are widely employed as nuclear materials, mechanical components, and wide-bandgap semiconductors. The rapid advancement of SiC-based applications has been complemented by computational modeling studies,…

Polymer-derived ceramics combine the thermal stability of ceramics with the versatile properties of carbon domains, but modeling their atomic-scale evolution during processing remains elusive due to the limitations of traditional…

The structure of surfaces and interfaces of silica (SiO2) is investigated by large scale molecular dynamics computer simulations. In the case of a free silica surface, the results of a classical molecular dynamics simulation are compared to…

Disordered Systems and Neural Networks · Physics 2007-05-23 Juergen Horbach , Torsten Stuehn , Claus Mischler , Walter Kob , Kurt Binder

This paper addresses a difficult inverse problem that involves the reconstruction of a three-dimensional model of tetrahedral amorphous semiconductors via inversion of diffraction data. By posing the material-structure determination as a…

Disordered Systems and Neural Networks · Physics 2019-12-06 Dil K. Limbu , Stephen R. Elliott , Raymond Atta-Fynn , Parthapratim Biswas

The structure of the first sharp diffraction peak (FSDP) of amorphous silicon (${\it a}$-Si) near 2 Angstrom$^{-1}$ is addressed with particular emphasis on the position, intensity, and width of the diffraction curve. By studying a number…

Disordered Systems and Neural Networks · Physics 2021-10-04 Devilal Dahal , Hiroka Warren , Parthapratim Biswas

We present a computational study of the electronic properties of amorphous SiO2. The ionic configurations used are the ones generated by an earlier molecular dynamics simulations in which the system was cooled with different cooling rates…

Disordered Systems and Neural Networks · Physics 2009-10-30 Thorsten Koslowski , Walter Kob , Katharina Vollmayr

We present a tight-binding calculation that, for the first time, accurately describes the structural, vibrational and elastic properties of amorphous silicon. We compute the interatomic force constants and find an unphysical feature of the…

Materials Science · Physics 2009-11-10 J. L. Feldman , N. Bernstein , D. A. Papaconstantopoulos , M. J. Mehl

A linear regression-based machine learned interatomic potential (MLIP) was developed for the silicon-carbon system. The MLIP was predominantly trained on structures discovered through a genetic algorithm, encompassing the entire…

Mesoscale and Nanoscale Physics · Physics 2024-03-26 Michael MacIsaac , Salil Bavdekar , Douglas Spearot , Ghatu Subhash

Machine learning (ML) based interatomic potentials are emerging tools for materials simulations but require a trade-off between accuracy and speed. Here we show how one can use one ML potential model to train another: we use an existing,…

Materials Science · Physics 2022-09-20 Joe D. Morrow , Volker L. Deringer

Recent advances in machine-learning interatomic potentials have enabled the efficient modeling of complex atomistic systems with an accuracy that is comparable to that of conventional quantum mechanics based methods. At the same time, the…

Materials Science · Physics 2021-05-06 April M. Miksch , Tobias Morawietz , Johannes Kästner , Alexander Urban , Nongnuch Artrith

Amorphous silicon films prepared by electron beam evaporation have systematically and substantially greater atomic density for higher thickness, higher growth temperature, and slower deposition rate, reaching the density of crystalline Si…

Materials Science · Physics 2022-04-27 H. C. Jacks , M. Molina-Ruiz , M. H. Weber , J. J. Maldonis , P. M. Voyles , T. H. Metcalf , X. Liu , F. Hellman

The 7\times7 reconstruction of the Si(111) surface represents arguably the most fascinating surface reconstruction so far observed in nature. Yet, the atomistic mechanism underpinning its formation remains unclear after it was discovered…

Materials Science · Physics 2021-05-05 Lin Hu , Bing Huang , Feng Liu

Machine learning interatomic potentials (MLIPs) are routinely used atomic simulations, but generating databases of atomic configurations used in fitting these models is a laborious process, requiring significant computational and human…

Materials Science · Physics 2022-07-26 Connor Allen , Albert P. Bartók