Equation of state and Hugoniot of warm dense xenon: Application of average atom-in-jellium model

Abstract

In warm dense xenon, thermally excited and pressure-ionized electrons are essential for calculating the equation of state; however, the classical Thomas Fermi model is unsuitable for describing this state. Therefore it is necessary to find an appropriate theoretical model to express the thermal characteristics of electrons in warm dense Xe. In this study, we use the average atom-in-jellium(AJ) model to compute the contribution of thermally excited and pressure-ionized electrons of Xe over a wide range of temperatures and densities. The electron resonance state in the AJ model is treated by the adaptive mesh movement method. Moreover a method for correcting the cold pressure curve(which is used in the liquid phase calculations) in the AJ model is proposed. For the liquid phase, the ion motion contribution is expressed by the liquid perturbation theory of the corrected rigid-ion sphere model. For the solid phase, the ion motion contribution is described by the Debye model combined with anharmonic correction. Our calculated Hugoniot curve of Xe coincides with those of the experiments, first-principles density functional calculations and other theoretical models. The melting line of Xe is also consistent with the results of first-principle calculations and other theoretical models.