RESEOS - A model of thermodynamic and optical properties of hot and warm dense matter

We present the equation-of-state and opacity calculations for hot and warm dense matter performed with the RESEOS code based on Liberman's average-atom model. The RESEOS model involves a generalized version of the superconfiguration approach providing a substantial simplification of the bound-bound absorption calculations. This simplification is gained by arranging the supershell gathering only among the subshells yielding a predominant contribution to the total dispersion of one-electron transition energies. The statistical broadening of narrow photoionization features connected with the spatial nonuniformity of the continuum-electron gas is modeled by using Gaussian profiles. The sensitivity of beryllium shock Hugoniot to the approximation to evaluate local exchange potential is examined and compared to experimental and other theoretical data. RESEOS shock Hugoniots and opacities are in a good agreement with experimental measurements and other calculated data obtained with up-to-date theoretical models.