TY - JOUR
T1 - Benchmarking vdW-DF first-principles predictions against Coupled Electron–Ion Monte Carlo for high-pressure liquid hydrogen
AU - Gorelov, Vitaly
AU - Pierleoni, Carlo
AU - Ceperley, David M.
N1 - V.G. and C.P. were supported by the Agence Nationale de la Recherche (ANR), France, under the program “Accueil de Chercheurs de Haut Niveau 2015” project: HyLightExtreme. D.M.C. was supported by a DOE Grant NA DE-NA0002911 and by the Fondation NanoSciences (Grenoble). Computer time was provided by PRACE Project 2016143296 and by an allocation of the Blue Waters sustained petascale computing project, supported by the National Science Foundation
This research was supported by the Agence Nationale de la Recherche, HyLightExtreme. National Science Foundation, OCI 07-25070. GENCI-CINES, 2018-A0030910282. State of Illinois. Fondation NanoSciences (Grenoble). DOE, NA DE-NA0002911.
information This research was supported by the Agence Nationale de la Recherche, HyLightExtreme. National Science Foundation, OCI 07-25070. GENCI-CINES, 2018-A0030910282. State of Illinois. Fondation NanoSciences (Grenoble). DOE, NA DE-NA0002911.V.G. and C.P. were supported by the Agence Nationale de la Recherche (ANR), France, under the program “Accueil de Chercheurs de Haut Niveau 2015” project: HyLightExtreme. D.M.C. was supported by a DOE Grant NA DE-NA0002911 and by the Fondation NanoSciences (Grenoble). Computer time was provided by PRACE Project 2016143296 and by an allocation of the Blue Waters sustained petascale computing project, supported by the National Science Foundation (Award OCI 07-25070) and the State of Illinois, and by the HPC resources from GENCI-CINES under the allocation 2018-A0030910282.
PY - 2019/5/1
Y1 - 2019/5/1
N2 - We report first-principles results for the nuclear structure and optical responses of high-pressure liquid hydrogen along two isotherms in the region of molecular dissociation. We employ density functional theory with the vdW-DF approximation (vdW) and benchmark the results against existing predictions from Coupled Electron–Ion Monte Carlo (CEIMC). At fixed density and temperature, we find that the pressure obtained from vdW is higher than that from CEIMC by about 10 GPa in the molecular insulating phase and about 20 GPa in the dissociated metallic phase. Molecules are found to be over-stabilized using vdW, with a slightly shorter bond length and with a stronger resistance to compression. As a consequence, pressure dissociation along isotherms using vdW is more progressive than that computed with CEIMC. Below the critical point, the liquid–liquid phase transition is observed with both theories in the same density region, but the one predicted by vdW has a smaller density discontinuity, i.e. a smaller first-order character. The optical conductivity computed using Kubo–Greenwood formulation is rather similar for the two systems and reflects the slightly more pronounced molecular character of vdW.
AB - We report first-principles results for the nuclear structure and optical responses of high-pressure liquid hydrogen along two isotherms in the region of molecular dissociation. We employ density functional theory with the vdW-DF approximation (vdW) and benchmark the results against existing predictions from Coupled Electron–Ion Monte Carlo (CEIMC). At fixed density and temperature, we find that the pressure obtained from vdW is higher than that from CEIMC by about 10 GPa in the molecular insulating phase and about 20 GPa in the dissociated metallic phase. Molecules are found to be over-stabilized using vdW, with a slightly shorter bond length and with a stronger resistance to compression. As a consequence, pressure dissociation along isotherms using vdW is more progressive than that computed with CEIMC. Below the critical point, the liquid–liquid phase transition is observed with both theories in the same density region, but the one predicted by vdW has a smaller density discontinuity, i.e. a smaller first-order character. The optical conductivity computed using Kubo–Greenwood formulation is rather similar for the two systems and reflects the slightly more pronounced molecular character of vdW.
KW - high-pressure hydrogen
KW - liquid structure
KW - liquid–liquid phase transition
KW - quantum Monte Carlo methods
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U2 - 10.1002/ctpp.201800185
DO - 10.1002/ctpp.201800185
M3 - Article
AN - SCOPUS:85061895359
SN - 0863-1042
VL - 59
JO - Contributions to Plasma Physics
JF - Contributions to Plasma Physics
IS - 4-5
M1 - e201800185
ER -