Accurate exchange-correlation energies for the warm dense electron gas
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
The density matrix quantum Monte Carlo (DMQMC) method is used to sample exact-on-average N-body density matrices for uniform electron gas systems of up to 10124 matrix elements via a stochastic solution of the Bloch equation. The results of these calculations resolve a current debate over the accuracy of the data used to parametrize finite-temperature density functionals. Exchange-correlation energies calculated using the real-space restricted path-integral formalism and the k-space configuration path-integral formalism disagree by up to ∼10% at certain reduced temperatures T/TF≤0.5 and densities rs≤1. Our calculations confirm the accuracy of the configuration path-integral Monte Carlo results available at high density and bridge the gap to lower densities, providing trustworthy data in the regime typical of planetary interiors and solids subject to laser irradiation. We demonstrate that the DMQMC method can calculate free energies directly and present exact free energies for T/TF≥1 and rs≤2.
Date Issued
2016-09-07
Date Acceptance
2016-08-02
Citation
Physical Review Letters, 2016, 117
ISSN
1079-7114
Publisher
American Physical Society
Journal / Book Title
Physical Review Letters
Volume
117
Copyright Statement
© 2016 American Physical Society.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
EPSRC
CSCS Swiss National Supercomputing Centre
Imperial College London
Engineering and Physical Sciences Research Council
Identifier
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.115701
Grant Number
EP/K038141/1
EPSRC RAP Call November 2014
Shepherd_2015_I
e494
Subjects
General Physics
Physical Sciences
Publication Status
Published
Article Number
ARTN 115701