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Title: Why Mg 2 IrH 6 Is Predicted to Be a High‐Temperature Superconductor, But Ca 2 IrH 6 Is Not
Abstract The X2MH6family, consisting of an electropositive cation Xn+and a main group metal M octahedrally coordinated by hydrogen, have been identified as promising templates for high‐temperature conventional superconductivity. Herein, we analyze the electronic structure of two members of this family, Mg2IrH6and Ca2IrH6, showing why the former may possess superconducting properties rivaling those of the cuprates, whereas the latter does not. Within Mg2IrH6the vibrations of the anions IrH64−anions are key for the superconducting mechanism, and they induce coupling in the set of orbitals, which are antibonding between the H 1sand the Ir or orbitals. Because calcium possesses low‐lyingd‐orbitals, →Cadback‐donation is preferred, quenching the superconductivity. Our analysis explains why high critical temperatures were only predicted for second or third row X metal atoms, and may provide rules for identifying likely high‐temperature superconductors in other systems where the antibonding anionic states are filled.  more » « less
Award ID(s):
2136038
PAR ID:
10598162
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
Angewandte Chemie International Edition
Date Published:
Journal Name:
Angewandte Chemie International Edition
Volume:
63
Issue:
52
ISSN:
1433-7851
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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