Comparison of Equations of State for Warm and Hot Dense Matter from REODP and PIMC Modeling*

Equations of State (EOS), transport and spectral properties of Warm and Hot Dense Matter (WDM and HDM denoted here as High Energy Density Matter (HEDM)) calculated from first principles are of great importance for understanding the processes in large planets, laser ablation, and inertial confinement fusion. The HEDM regime includes states of matter near solid density and at temperatures ~1 - 100 eV (WDM) and ~0.1 - 10 keV (HDM). A path integral Monte Carlo (PIMC) method is usually employed for calculating the EOS of HEDM. This is a statistical sampling approach that requires high computational time even for a single temperature-density point. The Hartree-Fock-Slater - Collisional-Radiative Steady-State (HFS-CRSS) model implemented in the Radiative Emissivity and Opacity of Dense Plasmas (REODP) code [Miloshevsky et al. PRE 92 (2015) 033109] is used to predict the EOS of HEDM. The internal energy and pressure for a large set of temperature-density points are computed within seconds on a desktop computer. Comparisons of the EOS for warm and hot dense carbon and other materials obtained from the REODP and PIMC models show very good agreement for wide ranges of temperature and density.