Development of uranium nitride crystals mathematical model for molecular dynamics simulation

A simple mathematical model of UN, U2N3, and UN2 crystals is used for reconstructing the pair potentials of interaction of the nearest neighbors and subsequent molecular dynamics simulation. The corresponding parameters of the U−N potential in U2N3 and UN2 crystals are obtained from the experimental values of the lattice constant and the bulk moduli of UN, U2N3, UN2 at room temperature. The linear expansion coefficients of U2N3 and UN2 crystals, as well as the U2N3 bulk modulus are estimated within the harmonic approximation. The dependences of the U2N3 and UN2 lattice constants on temperature are calculated by the molecular dynamics method.