Wave Packet Molecular Dynamics simulations of hydrogen at mbar pressures

Abstract

In this paper we apply Wave Packet Molecular Dynamics simulations to the equation of state of hydrogen. This method was originally used by Heller for a description of the scattering of composite particles like simple atoms and molecules [J. Chem. Phys. 62 (1975) 1544] [1]; later it was applied to Coulomb systems by Klakow et al. [Phys. Lett. A 192 (1994) 55; J. Chem. Phys. 101 (1994) 10 766] [2,3]. In the present version of the method 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. In contrast to other ab-initio methods [Phys. Rev. Lett. 85 (2000) 1890; Phys. Rev. E 63 (2001) 066404] [10,11] the Slater sums can be evaluated by a numerically stable and affordable matrix inversion [Nucl. Instrum. and Meth. A 464 (2000) 267] [5].