Uniform electron gas at finite temperatures

TL;DR

This paper computes the free energy of the quantum uniform electron gas across a wide temperature range, extending theoretical models, and providing accurate fits for practical use.

Contribution

It extends the Vashista-Singwi theory to finite temperatures with a self-consistent compressibility sum rule and compares results with other methods and simulations.

Findings

Extended theory matches quantum Monte Carlo results

Provided accurate exchange-correlation free energy fits

Demonstrated the approach's applicability across temperature regimes

Abstract

We calculate the free energy of the quantum uniform electron gas for temperatures from near zero to 100 times the Fermi energy, approaching the classical limit. An extension of the Vashista-Singwi theory to finite temperatures and self-consistent compressibility sum rule is presented. Comparisons are made to other local field correction methods, as well as recent quantum Monte Carlo simulation and classical map based results. Accurate fits to the exchange-correlation free energy from both theory and simulation are given for future practical applications.