Evaluation of Phonon-level Density of UO₂ by Molecular Dynamics Simulation

Molecular dynamics calculation of UO₂ in a wide temperature range are presented and dis-cussed. The calculated lattice parameters, mean square displacements, and dynamic prop-erty of phonon-level density of the velocity auto-correlation functions for UO₂ are provided. The Morelon potential and the Basak potential are employed. It confirms that the cal-culated lattice parameters using the Basak potential are in nearly perfect agreement with the reported values. The models successfully predict mean square displacement and Bredig transition. Furthermore, the phonon-level density of uranium dioxide are discussed. The intensity of phonon-level density increases with temperature, and the properties of UO₂ are characterized by large thermal vibrations rather than extensive disorder.