Ab Initio Study of Structure and Transport Properties of Warm Dense Nitric Oxide

Abstract

The structure, equation of state and transport properties of warm dense nitric oxide (NO) were investigated in wide density and temperature ranges by ab initio molecular dynamics simulations. Both the Perdew–Burke–Ernzerhof (PBE) and the strongly constrained and appropriately normed functional with revised Vydrov–van Voorhis nonlocal correlation (SCAN−rVV10) functionals were used in the simulations, and the pressures predicted by the SCAN−rVV10 functional were found to be systematically lower than those predicted using PBE and experimental data along the shock Hugoniot curve. Along the Hugoniot curve, as density increased, we found that the system transformed towards a mixture of atomic nitrogen and oxygen liquids with molecular NO that remained present up to the highest densities explored. The electrical conductivity along Hugoniot indicated that nonmetal to metal transition had taken place. We also calculated the electrical and thermal conductivities of nitric oxide in the warm dense matter regime, and used them to compute the Lorentz number. In addition, we also report the electronic density of states.