A Unified Ionic Model for Molecular Dynamics Simulation of UC, U2C3 and UC2 Crystals

A technique is proposed for the recovery of pair potentials for the interaction of intrinsic ions in crystals. Using this approach, a unified set of empirical pair interaction potentials for simulation of uranium carbide crystals UnCm in the ionic approximation by the method of molecular dynamics is obtained. The potential parameters are determined from the experimental values of the lattice constant and the UC, U2C3, UC2 bulk compression moduli, as well as the linear expansion coefficient of UC crystal at room temperature. The temperature dependences of the lattice constants and the coefficients of linear expansion of the model uranium carbide nanocrystals are calculated using the suggested potentials. The dependence of the melting temperature of the model nanocrystals on composition is also discussed.