Molecular Dynamics Study of Uranium Nitride

We have investigated thermal properties of uranium nitride using classical molecular dynamics simulations. Key material properties, including defect formation energies, elastic constants, mechanical moduli, atomic diffusivity, and thermal conductivity, were systematically calculated and validated against experimental and theoretical references. The results demonstrate that the angular-dependent potential (ADP) force field accurately reproduces the structural and thermophysical behavior of UN, particularly capturing its distinctive thermal conductivity enhancement at high temperatures. This unusual positive temperature dependence, supported by nitrogen's high self-diffusivity, reinforces UN’s suitability as an advanced nuclear fuel. The validated U–N parameterization provides a robust computational foundation for future extensions involving fission products, enabling predictive simulations of their impact on fuel integrity and performance under irradiation conditions.