Yukawa Monte Carlo and Orbital Free Molecular Dynamics approaches for the equation of state and structural properties of hot dense matter

Molecular Dynamics (MD) and Monte Carlo (MC) simulations techniques have been extensively employed to obtain accurate results on the structural and dynamical properties of hot dense matter. Among them, Yukawa MC(YMC) and MD simulations are powerful techniques to compute plasma properties such as equation of state (EOS) or transport coefficients, but are, in principle, limited to applications where the linear electronic screening assumption is valid. On the contrary, it has been recently shown that a modified scheme using density functional theory with a Thomas-Fermi kinetic energy functional for the electrons may be well suited to perform MD simulations on high Z elements at high densities and temperature, without any assumption on the electronic screening. Since Yukawa theory is based on several assumptions and parameters, our purpose in this paper is to check some of these approximations by the Orbital Free Molecular Dynamics (OFMD) scheme, that goes beyond the classical models. For several selected iron plasma conditions, we have compared YMC and OFMD pair correlation functions and equation of state. This provides the opportunity to discuss the influence of the primary parameter for Yukawa potentials, i.e. the ionization of the plasma in the hot and dense regime. (C) 2007 Elsevier B.V. All rights reserved.