Abstracto

Simulation of isothermal processes in uranium dioxide through molecular dynamics method using a parametrically temperature-dependent potential

Yuri Sergeevich Nagornov, Andrey Valerievich Katz

The present paper justifies the application of the temperature-dependent potential to themolecular dynamicsmethod through the example of uranium dioxide. Substantiation of the temperature dependence of interatomic potential is carried out based on the Newton quantum equation.Mean force can be represented as a sum of derivative of potential at the average atomic coordinate and the summand that depends on square dispersion of the coordinate depending on the temperature of the crystal. The selection of parameters of potential was done at three temperature values: the initial temperature and temperatures of phase transitions – 2670 and 3120K, parameters of potentials for all other temperatures were found by approximation. The paper calculated temperature dependencies for the lattice constant, enthalpy, heat capacity. Our data are good agreement with experimental data.