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Title: Dilute carbon in H3S under pressure
Abstract Recently, room temperature superconductivity was measured in a carbonaceous sulfur hydride material whose identity remains unknown. Herein, first-principles calculations are performed to provide a chemical basis for structural candidates derived by doping H3S with low levels of carbon. Pressure stabilizes unusual bonding configurations about the carbon atoms, which can be six-fold coordinated as CH6entities within the cubic H3S framework, or four-fold coordinated as methane intercalated into the H-S lattice, with or without an additional hydrogen in the framework. The doping breaks degenerate bands, lowering the density of states at the Fermi level (NF), and localizing electrons in C-H bonds. Low levels of CH4doping do not increaseNFto values as high as those calculated for$$Im\bar{3}m$$ I m 3 ¯ m -H3S, but they can yield a larger logarithmic average phonon frequency, and an electron–phonon coupling parameter comparable to that ofR3m-H3S. The implications of carbon doping on the superconducting properties are discussed.  more » « less
Award ID(s):
2104881
PAR ID:
10366509
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Nature Publishing Group
Date Published:
Journal Name:
npj Computational Materials
Volume:
8
Issue:
1
ISSN:
2057-3960
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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