  Macroscopic simulations of dense plasmas rely on detailed microscopic
information that can be computationally expensive and is difficult to verify
experimentally. In this work, we delineate the accuracy boundary between
microscale simulation methods by comparing Kohn-Sham density functional theory
molecular dynamics (KS-MD) and radial pair potential molecular dynamics (RPP-
MD) for a range of elements, temperature, and density. By extracting the
optimal RPP from KS-MD data using force-matching, we constrain its functional
form and dismiss classes of potentials that assume a constant power law for
small interparticle distances. Our results show excellent agreement between
RPP-MD and KS-MD for multiple metrics of accuracy at temperatures of only a few
electron volts. The use of RPPs offers orders of magnitude decrease in
computational cost and indicates that three-body potentials are not required
beyond temperatures of a few eV. Due to its efficiency, the validated RPP-MD
provides an avenue for reducing errors due to finite-size effects that can be
on the order of $\sim20\%$.
