PSI - Issue 65

ScienceDirect Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2024) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2024) 000–000 Available online at www.sciencedirect.com

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Procedia Structural Integrity 65 (2024) 127–132

The 17th International Conference on MECHANICS, RESOURCE AND DIAGNOSTICS OF MATERIALS AND STRUCTURES (MRDMS 2023) Molecular dynamics analysis of interatomic potentials of vanadium using exact solutions of the equations of atomic motion I.V. Kosarev a,b, *, E.A. Korznikova b,c , S.V. Dmitriev a,c a Institute of Molecule and Crystal Physics, UFRC of Russian Academy of Sciences, 450075 Ufa, Russia b Youth Research Laboratory “Metals and Alloys under Extreme Impacts”, Ufa University of Science and Technology, 450076 Ufa, Russia c Polytechnic Institute (branch) in Mirny, M.K. Ammosov North-Eastern Federal University, 678179 Mirny, Russia This paper describes a special class of exact solutions to the equations of motion of atoms in a bcc lattice, which exist for every chemical element with such a lattice. Such exact solutions are called delocalized nonlinear vibrational modes (DNVMs). We propose to use 14 single-component short-wavelength DNVMs of the bcc lattice to compare their frequency responses calculated for vanadium using the molecular dynamics method with different interatomic potentials. In the harmonic (small-amplitude) approximation, different potentials give a good estimate of the DNVM vibrational frequencies, but for molecular dynamics the anharmonic (nonlinear) vibrations are of key importance. The DNVMs under consideration are derived from the bush theory developed by Chechin and Sakhnenko and correspond in the low amplitude range to phonon modes with a wave vector at highly symmetric points on the boundary of the first Brillouin zone. However, due to the high symmetry of the oscillations, DNVMs do not interact with other phonon modes even at large amplitudes and thus characterize the nonlinear part of the frequency responses. The frequency responses of DNVMs have been calculated for vanadium with three classical and one machine-learned interatomic potential using the LAMMPS software package, and a significant discrepancy of the results in the nonlinear region has been shown. Thus, the need to improve modern approaches to the development and testing of interatomic potentials is demonstrated. © 2024 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of MRDMS 2023 organizers Keywords: molecular dynamics, bcc vanadium, DNVMs. The 17th International Conference on MECHANICS, RESOURCE AND DIAGNOSTICS OF MATERIALS AND STRUCTURES (MRDMS 2023) Molecular dynamics analysis of interatomic potentials of vanadium using exact solutions of the equations of atomic motion I.V. Kosarev a,b, *, E.A. Korznikova b,c , S.V. Dmitriev a,c a Institute of Molecule and Crystal Physics, UFRC of Russian Academy of Sciences, 450075 Ufa, Russia b Youth Research Laboratory “Metals and Alloys under Extreme Impacts”, Ufa University of Science and Technology, 450076 Ufa, Russia c Polytechnic Institute (branch) in Mirny, M.K. Ammosov North-Eastern Federal University, 678179 Mirny, Russia Abstract This paper describes a special class of exact solutions to the equations of motion of atoms in a bcc lattice, which exist for every chemical element with such a lattice. Such exact solutions are called delocalized nonlinear vibrational modes (DNVMs). We propose to use 14 single-component short-wavelength DNVMs of the bcc lattice to compare their frequency responses calculated for vanadium using the molecular dynamics method with different interatomic potentials. In the harmonic (small-amplitude) approximation, different potentials give a good estimate of the DNVM vibrational frequencies, but for molecular dynamics the anharmonic (nonlinear) vibrations are of key importance. The DNVMs under consideration are derived from the bush theory developed by Chechin and Sakhnenko and correspond in the low amplitude range to phonon modes with a wave vector at highly symmetric points on the boundary of the first Brillouin zone. However, due to the high symmetry of the oscillations, DNVMs do not interact with other phonon modes even at large amplitudes and thus characterize the nonlinear part of the frequency responses. The frequency responses of DNVMs have been calculated for vanadium with three classical and one machine-learned interatomic potential using the LAMMPS software package, and a significant discrepancy of the results in the nonlinear region has been shown. Thus, the need to improve modern approaches to the development and testing of interatomic potentials is demonstrated. © 2024 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of MRDMS 2023 organizers Keywords: molecular dynamics, bcc vanadium, DNVMs. © 2024 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of MRDMS 2023 organizers Abstract

* Corresponding author. Tel.: +7-937-495-5250. E-mail address: igor.v.kosarev@gmail.com * Corresponding author. Tel.: +7-937-495-5250. E-mail address: igor.v.kosarev@gmail.com

2452-3216 © 2024 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of MRDMS 2023 organizers 2452-3216 © 2024 The Authors, Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of MRDMS 2023 organizers

2452-3216 © 2024 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of MRDMS 2023 organizers 10.1016/j.prostr.2024.11.020