Toward machine learning interatomic potentials for modeling uranium mononitride

Fuente: arXiv
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Autori principali: Alzate-Vargas, Lorena, Subedi, Kashi N., Lubbers, Nicholas, Cooper, Michael W. D, Tutchton, Roxanne M., Gibson, Tammie, Messerly, Richard A.
Natura: Preprint
Pubblicazione: 2024
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author Alzate-Vargas, Lorena
Subedi, Kashi N.
Lubbers, Nicholas
Cooper, Michael W. D
Tutchton, Roxanne M.
Gibson, Tammie
Messerly, Richard A.
author_facet Alzate-Vargas, Lorena
Subedi, Kashi N.
Lubbers, Nicholas
Cooper, Michael W. D
Tutchton, Roxanne M.
Gibson, Tammie
Messerly, Richard A.
contents Uranium mononitride (UN) is a promising accident-tolerant fuel because of its high fissile density and high thermal conductivity. In this study, we developed the first machine learning interatomic potentials for reliable atomic-scale modeling of UN at finite temperatures. We constructed a training set using density functional theory (DFT) calculations that was enriched through an active learning procedure, and two neural network potentials were generated. Both potentials successfully reproduce key thermophysical properties of interest, such as temperature-dependent lattice parameter, specific heat capacity, and bulk modulus. We also evaluated the energy of stoichiometric defect reactions and defect migration barriers and found close agreement with DFT predictions, demonstrating that our potentials can be used for modeling defects in UN. Additional tests provide evidence that our potentials are reliable for simulating diffusion, noble gas impurities, and radiation damage.
format Preprint
id arxiv_https___arxiv_org_abs_2411_14608
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Toward machine learning interatomic potentials for modeling uranium mononitride
Alzate-Vargas, Lorena
Subedi, Kashi N.
Lubbers, Nicholas
Cooper, Michael W. D
Tutchton, Roxanne M.
Gibson, Tammie
Messerly, Richard A.
Materials Science
Uranium mononitride (UN) is a promising accident-tolerant fuel because of its high fissile density and high thermal conductivity. In this study, we developed the first machine learning interatomic potentials for reliable atomic-scale modeling of UN at finite temperatures. We constructed a training set using density functional theory (DFT) calculations that was enriched through an active learning procedure, and two neural network potentials were generated. Both potentials successfully reproduce key thermophysical properties of interest, such as temperature-dependent lattice parameter, specific heat capacity, and bulk modulus. We also evaluated the energy of stoichiometric defect reactions and defect migration barriers and found close agreement with DFT predictions, demonstrating that our potentials can be used for modeling defects in UN. Additional tests provide evidence that our potentials are reliable for simulating diffusion, noble gas impurities, and radiation damage.
title Toward machine learning interatomic potentials for modeling uranium mononitride
topic Materials Science
url https://arxiv.org/abs/2411.14608