Efficacy of the Radial Pair Potential Approximation for Molecular Dynamics Simulations of Dense Plasmas

To accurately model ongoing and proposed inertial confinement fusion platforms, accurate equations-of-state for bulk systems are not enough to account for inhomogeneities, interfaces, and multispecies transport. The evolution of a macroscopic interface is heavily determined by the electron and ion interactions which can not be approximated classically at lower temperatures due to degenerate electrons and strongly-coupled ions. We propose an approach to benchmark and validate the assumptions underpinning a large class of transport models, complementary to ongoing experimental efforts at several national labs. Specifically, by force-matching radial pair potentials and many-body potentials to Kohn-Sham density functional theory data across a range of elements, densities, and temperatures, we are able to directly assess the quality of the pair potential approximation invoked in several transport theories using multiple metrics of accuracy. Beyond providing rough accuracy boundaries, this approach allows for a comparison between Kohn-Sham density functional theory and existing transport theories, potentially allowing one to tweak or improve more computationally affordable pair potential ansatzë.