2015/09/30 by Matej Komelj, Henry Krakauer · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Ab initio #Advanced Chemical Physics Studies #Anharmonicity #Condensed matter physics #Coupling (piping) #Density functional theory #Electron #Electronic correlation #High-pressure geophysics and materials #Materials science #Perturbation theory (quantum mechanics) #Phonon #Physics #Quantum mechanics #Superconductivity #Superconductivity in MgB2 and Alloys #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.92.205125
published as Phys. Rev. B 92, 205125 (2015)
openalex publication_date 2015/11/23 · arxiv created 2015/11/27 · arxiv updated 2015/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate the H3S phase of sulfur hydride under high pressure \ensuremath≃200 GPa by means of ab initio calculations within the framework of the density-functional theory with the PBE0 hybrid exchange-correlation (Exc) approximation. The choice of Exc has the largest effect on the calculated electron-phonon coupling (EPC) matrix elements; the high-pressure equation of state and phonon frequencies are only slightly modified. Mode-dependent EPC correction factors are determined from PBE0 using a frozen-phonon supercell approach, while standard density-functional perturbation theory is used to determine the EPC with PBE generalized-gradient approximation Exc. Our principle finding is that the calculated PBE0 Tc is enhanced by 25% compared to PBE. This is similar in magnitude, but in opposite direction, to the proposed suppression of Tc by anharmonic effects [I. Errea et al., Phys. Rev. Lett. 114, 157004 (2015)]. Our calculations demonstrate the importance of considering exchange-correlation approximations for calculations of superconducting properties for this class of materials.