Ab initio exchange-correlation free energy of the uniform electron gas at warm dense matter conditions

Title: Ab initio exchange-correlation free energy of the uniform electron gas at warm dense matter conditions
Author(s): Groth, S
Dornheim, T
Sjostrom, T
Malone, FD
Foulkes, WMC
Bonitz, M
Item Type: Journal Article
Abstract: In a recent Letter [T.~Dornheim \textit{et al.}, Phys. Rev. Lett. \textbf{117}, 156403 (2016)], we presented the first \textit{ab initio} quantum Monte-Carlo (QMC) results of the warm dense electron gas in the thermodynamic limit. However, a complete parametrization of the exchange-correlation free energy with respect to density, temperature, and spin polarization remained out of reach due to the absence of (i) accurate QMC results below $\theta=k_\text{B}T/E_\text{F}=0.5$ and (ii) of QMC results for spin polarizations different from the paramagnetic case. Here we overcome both remaining limitations. By closing the gap to the ground state and by performing extensive QMC simulations for different spin polarizations, we are able to obtain the first complete \textit{ab initio} exchange-correlation free energy functional; the accuracy achieved is an unprecedented $\sim 0.3\%$. This also allows us to quantify the accuracy and systematic errors of various previous approximate functionals.
Publication Date: 28-Sep-2017
Date of Acceptance: 22-Aug-2017
URI: http://hdl.handle.net/10044/1/53350
DOI: https://dx.doi.org/10.1103/PhysRevLett.119.135001
ISSN: 0031-9007
Publisher: American Physical Society
Journal / Book Title: Physical Review Letters
Volume: 119
Issue: 13
Copyright Statement: © 2017 American Physical Society
Sponsor/Funder: Engineering & Physical Science Research Council (EPSRC)
EPSRC
CSCS Swiss National Supercomputing Centre
Imperial College London
Engineering and Physical Sciences Research Council
Funder's Grant Number: EP/K038141/1
EPSRC RAP Call November 2014
Shepherd_2015_I
e494
Keywords: Science & Technology
Physical Sciences
Physics, Multidisciplinary
Physics
EQUATION-OF-STATE
COLLECTIVE DESCRIPTION
GROUND-STATE
MONTE-CARLO
PLASMAS
LIQUIDS
SYSTEMS
THERMODYNAMICS
APPROXIMATION
TEMPERATURES
physics.plasm-ph
physics.plasm-ph
cond-mat.stat-mech
physics.plasm-ph
physics.plasm-ph
cond-mat.stat-mech
02 Physical Sciences
General Physics
Publication Status: Published
Article Number: 135001
Appears in Collections:Condensed Matter Theory
Physics
Faculty of Natural Sciences



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