skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on November 26, 2019

Title: Evaluation of exchange-correlation functionals with multiple-shock conductivity measurements in hydrogen and deuterium at the molecular-to-atomic transition

Abstract

The temperature ( T) and density (ρ) conditions at which hydrogen undergoes a molecular-to-atomic (MA) transition is crucial to our understanding of the gas-giant planets such as Jupiter and Saturn. First-principles (FP) calculations suggest that this transition is coincident with metallization and acts as a catalyst for hydrogen-helium demixing, which has significant consequences for models of planetary interiors. Prediction of this transition boundary has proven to be difficult using FP methods. In particular, detailed comparisons of finite temperature density functional theory (FT-DFT) calculations of the MA transition in both the high- T, low-ρ regime, where the transition is largely T driven, and the low- T, high-ρ regime, where the transition is largely ρ driven, suggest that the transition is very sensitive to the exchange-correlation (xc) functional used in the calculation. Here we present a detailed comparison of previous multiple-shock electrical conductivity measurements with FT-DFT calculations employing various xc functionals to probe a regime where both T and ρ play an important role in the transition. The measurement results are found to be inconsistent with the semilocal xc functional PBE and are in much better agreement with the nonlocal xc functionals vdW-DF1 and vdW-DF2. Furthermore, we show that the inconsistency withmore » PBE likely stems from pressure errors associated with the PBE xc functional, resulting in calculated pressures that are too low at these T and ρ conditions. Together with previous comparisons at high- T, low-ρ and low- T, high-ρ these results provide a consistent picture for the MA transition over a wide T and ρ range. Here, this picture may also provide insight into differences in experimental observations of the metallization of liquid hydrogen and deuterium in the low- T regime.« less

Authors:
 [1];  [2];  [3];  [3]
  1. Washington State Univ., Pullman, WA (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  3. Univ. of Rostock, Rostock (Germany)
Publication Date:
Research Org.:
Washington State Univ., Pullman, WA (United States). Inst. for Shock Physics
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Programs (DP) (NA-10)
OSTI Identifier:
1493764
Alternate Identifier(s):
OSTI ID: 1492145
Grant/Contract Number:  
NA0002007; NA0003525
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 98; Journal Issue: 17; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 08 HYDROGEN

Citation Formats

Knudson, M. D., Desjarlais, M. P., Preising, M., and Redmer, R. Evaluation of exchange-correlation functionals with multiple-shock conductivity measurements in hydrogen and deuterium at the molecular-to-atomic transition. United States: N. p., 2018. Web. doi:10.1103/PhysRevB.98.174110.
Knudson, M. D., Desjarlais, M. P., Preising, M., & Redmer, R. Evaluation of exchange-correlation functionals with multiple-shock conductivity measurements in hydrogen and deuterium at the molecular-to-atomic transition. United States. doi:10.1103/PhysRevB.98.174110.
Knudson, M. D., Desjarlais, M. P., Preising, M., and Redmer, R. Mon . "Evaluation of exchange-correlation functionals with multiple-shock conductivity measurements in hydrogen and deuterium at the molecular-to-atomic transition". United States. doi:10.1103/PhysRevB.98.174110.
@article{osti_1493764,
title = {Evaluation of exchange-correlation functionals with multiple-shock conductivity measurements in hydrogen and deuterium at the molecular-to-atomic transition},
author = {Knudson, M. D. and Desjarlais, M. P. and Preising, M. and Redmer, R.},
abstractNote = {The temperature (T) and density (ρ) conditions at which hydrogen undergoes a molecular-to-atomic (MA) transition is crucial to our understanding of the gas-giant planets such as Jupiter and Saturn. First-principles (FP) calculations suggest that this transition is coincident with metallization and acts as a catalyst for hydrogen-helium demixing, which has significant consequences for models of planetary interiors. Prediction of this transition boundary has proven to be difficult using FP methods. In particular, detailed comparisons of finite temperature density functional theory (FT-DFT) calculations of the MA transition in both the high-T, low-ρ regime, where the transition is largely T driven, and the low-T, high-ρ regime, where the transition is largely ρ driven, suggest that the transition is very sensitive to the exchange-correlation (xc) functional used in the calculation. Here we present a detailed comparison of previous multiple-shock electrical conductivity measurements with FT-DFT calculations employing various xc functionals to probe a regime where both T and ρ play an important role in the transition. The measurement results are found to be inconsistent with the semilocal xc functional PBE and are in much better agreement with the nonlocal xc functionals vdW-DF1 and vdW-DF2. Furthermore, we show that the inconsistency with PBE likely stems from pressure errors associated with the PBE xc functional, resulting in calculated pressures that are too low at these T and ρ conditions. Together with previous comparisons at high-T, low-ρ and low-T, high-ρ these results provide a consistent picture for the MA transition over a wide T and ρ range. Here, this picture may also provide insight into differences in experimental observations of the metallization of liquid hydrogen and deuterium in the low-T regime.},
doi = {10.1103/PhysRevB.98.174110},
journal = {Physical Review B},
number = 17,
volume = 98,
place = {United States},
year = {2018},
month = {11}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on November 26, 2019
Publisher's Version of Record

Save / Share:

Works referenced in this record:

Generalized Gradient Approximation Made Simple
journal, October 1996

  • Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
  • Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
  • DOI: 10.1103/PhysRevLett.77.3865

Special points for Brillouin-zone integrations
journal, June 1976

  • Monkhorst, Hendrik J.; Pack, James D.
  • Physical Review B, Vol. 13, Issue 12, p. 5188-5192
  • DOI: 10.1103/PhysRevB.13.5188

Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set
journal, October 1996


Ab initio molecular-dynamics simulation of the liquid-metal�amorphous-semiconductor transition in germanium
journal, May 1994


Ab initiomolecular dynamics for liquid metals
journal, January 1993