We present extensive new \emph{ab initio} path integral Monte Carlo (PIMC) simulations of the uniform electron gas (UEG) in the high-temperature regime, 8≤θ=kBT/EF≤128. This allows us to study the convergence of different properties towards the classical limit. In particular, we investigate the classical relation between the static structure factor S(q) and the static local field correction G(q), which is only fulfilled at low densities. Moreover, we compare our new results for the interaction energy to the parametrization of the UEG by Groth \emph{et al.}~[PRL \textbf{119}, 135001 (2017)], which interpolates between PIMC results for θ≤8 and the Debye-H\"uckel limit, and to higher order analytical virial expansions. Finally, we consider the momentum distribution function n(q) and find an interaction-induced increase in the occupation of the zero-momentum state even for θ≳32. All PIMC data are freely available online, and can be used as input for improved parametrizations and as a rigorous benchmark for approximate methods.
@article{arxiv.2202.02736,
title = {The uniform electron gas at high temperatures: \emph{ab initio} path integral Monte Carlo simulations and analytical theory},
author = {Tobias Dornheim and Jan Vorberger and Zhandos Moldabekov and Gerd Röpke and Wolf-Dietrich Kraeft},
journal= {arXiv preprint arXiv:2202.02736},
year = {2022}
}