Wave packet molecular dynamics simulations of warm dense hydrogen

Abstract

Recent shock-wave experiments with deuterium [1, 2] in a regime where a plasma phase-transition has been predicted [3] and their theoretical interpretation are the matter of a controversial discussion (see e.g. [4–8]). In this paper, we apply 'wave packet molecular dynamics' (WPMD) simulations to investigate warm dense hydrogen. The WPMD method was originally used by Heller for a description of the scattering of composite particles such as simple atoms and molecules [9]; later it was applied to Coulomb systems by Klakow et al [10, 11]. In the present version of our model the protons are treated as classical point-particles, whereas the electrons are represented by a completely anti-symmetrized Slater sum of periodic Gaussian wave packets. We present recent results for the equation of state of hydrogen at constant temperature T = 300 K and of deuterium at constant Hugoniot E − E0 + 1/2(1/n − 1/n0)(p + p0) = 0, and compare them with the experiments and several theoretical approaches.