Analysis of semi-classical potentials for molecular dynamics and Monte Carlo simulations of warm dense matter

Effective, semi-classical potentials may present a powerful tool for the determination of properties of warm dense matter, systems characterized by both moderate coupling and moderate degeneracy. However, this requires the use of these potentials in a regime where the approximations employed in their derivation begin to break down. This work presents a careful analysis of the methodology and approximations used to derive semi-classical potentials for Coulomb systems. Particular attention is paid to the appearance of many-body effects and the techniques that may be used to model them. Analytical arguments and simple examples indicate that the role of many-body effects cannot be ignored in the warm dense matter regime, and those semi-classical Coulomb potentials that focus on the pair interaction do not adequately treat many-body effects. (C) 2007 Elsevier B.V. All rights reserved.