Correlation energy of the paramagnetic electron gas at the thermodynamic limit

TL;DR

This paper uses advanced quantum Monte Carlo methods to accurately calculate the correlation energy of the paramagnetic electron gas at the thermodynamic limit, improving upon previous results for high-density systems.

Contribution

It provides more accurate correlation energies for the paramagnetic electron gas by employing twist-averaged boundary conditions and extrapolation techniques, enhancing density functional parameterization.

Findings

Correlation energies are lower than previous results.

Finite-size errors are effectively removed.

Results are suitable for high-density system modeling.

Abstract

The variational and diffusion quantum Monte Carlo methods are used to calculate the correlation energy of the paramagnetic three-dimensional homogeneous electron gas at intermediate to high density. Ground state energies in finite cells are determined using Slater-Jastrow-backflow trial wave functions, and finite-size errors are removed using twist-averaged boundary conditions and extrapolation of the energy per particle to the thermodynamic limit of infinite system size. Our correlation energies in the thermodynamic limit are lower (i.e., more negative, and therefore more accurate according to the variational principle) than previous results, and can be used for the parameterization of density functionals to be applied to high-density systems.