Improved first-principles equation-of-state table of deuterium for high-energy-density applications

Journal Article · Tue Oct 12 00:00:00 EDT 2021 · Physical Review B

DOI:https://doi.org/10.1103/physrevb.104.144104· OSTI ID:1829728

Mihaylov, D. I. ^[1]; Karasiev, V. V. ^[1]; Hu, S. X. ^[1]; Rygg, J. R. ^[1]; Goncharov, V. N. ^[1]; Collins, G. W. ^[1]

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1. Univ. of Rochester, NY (United States). Lab. for Laser Energetics

Here, we present a first-principles equation-of-state (EOS) table of deuterium aimed at improving the previously established first-principles equation-of-state table (FPEOS). The EOS table presented here, referred to as iFPEOS, introduces (1) a universal density functional theory (DFT) treatment of all density and temperature conditions, (2) a fully consistent treatment of exchange-correlation (XC) thermal effects across the entire range of temperatures covered, and (3) quantum treatment of ions. Based on ab initio molecular dynamics driven by thermal density functional theory, iFPEOS includes density points in the range 1×10^–3 $$\leqslant$$ ρ $$\leqslant$$ 1.6×10³ g/cm³ and temperature points in the range 800 K $$\leqslant$$ T $$\leqslant$$ 256 MK, thus covering the challenging warm dense matter (WDM) regime. For an improved description of the electronic structure, iFPEOS employs an advanced free-energy XC density functional with explicit temperature dependence, which is at the metageneralized gradient approximation level of DFT. We use the latest orbital-free free-energy density functional for the high-temperature regime where it shows excellent agreement with standard Mermin-Kohn-Sham DFT. For quantum treatment of ions we use path-integral molecular dynamics in order to take into account nuclear quantum effects. Results are compared to other EOS models and most recent experimental measurements of deuterium properties such as the molecular-toatomic fluid transition, the principal and reshock Hugoniot, and sound speed. We find that iFPEOS provides an improved agreement with experimental data compared to other first-principles EOS models in the WDM regime for pressures up to 200 GPa and temperatures up to 60 000 K. For higher pressures and temperatures, however, iFPEOS is in agreement with other models in predicting lower compressibility and higher sound speed along the Hugoniot, compared to experiment.

• Research Organization: Univ. of Rochester, NY (United States). Lab. for Laser Energetics
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC); National Science Foundation (NSF)
• Grant/Contract Number: NA0003856; AC02-05CH11231; PHY-1802964
• OSTI ID: 1829728
• Journal Information: Physical Review B, Vol. 104, Issue 14; ISSN 2469-9950
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY