[1C01-05] Elementary Reaction, Fundamental Physical Properties, Simulated FP

[1C04] The Bredig transition and physical property change in CaF₂

(2)Machine-Learning Molecular Dynamics Study

*Hiroki Nakamura¹, Masahiko Machida¹, Masashi Watanabe¹, Masato Kato¹ (1. JAEA)

Keywords:CaF2, Machine-learning molecular dynamics, Bredig transition, Inelastic neutron scattering, First-principles calculation

It is difficult to measure the thermal properties of nuclear fuel materials such as uranium dioxide, at high temperature just below their melting points. CaF₂ is sometimes employed as alternative nuclear fuel materials. In this paper, we evaluate the Bredig transition and its effect on the materials properties, using machine-learning molecular dynamics trained by first-principles calculations. In particular, we investigate the dynamical structure factor measured by inelastic neutron scattering, and we explore the characteristics of the Bredig transition. We also discuss application to nuclear materials such as uranium dioxide.