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Title: Benchmarking exchange-correlation functionals for hydrogen at high pressures using quantum Monte Carlo

The ab initio phase diagram of dense hydrogen is very sensitive to errors in the treatment of electronic correlation. Recently, it has been shown that the choice of the density functional has a large effect on the predicted location of both the liquid-liquid phase transition and the solid insulator-to-metal transition in dense hydrogen. To identify the most accurate functional for dense hydrogen applications, we systematically benchmark some of the most commonly used functionals using quantum Monte Carlo. By considering several measures of functional accuracy, we conclude that the van der Waals and hybrid functionals significantly outperform local density approximation and Perdew-Burke-Ernzerhof. We support these conclusions by analyzing the impact of functional choice on structural optimization in the molecular solid, and on the location of the liquid-liquid phase transition.
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [1] ;  [2]
  1. Univ. of Illinois, Urbana, IL (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. Istituto Nazionale di Fisica Nucleare (INFN), L'aquila (Italy). Lab. Nazionali del Gran Sasso (INFN-LNGS)
Publication Date:
OSTI Identifier:
1136141
DOE Contract Number:
AC52-07NA27344; NA0001789
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 89; Journal Issue: 18
Publisher:
American Physical Society (APS)
Research Org:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY