First-principles search of hot superconductivity in La-X-H ternary hydrides

Abstract Motivated by the recent claim of hot superconductivity with critical temperatures up to 550 K in La + x hydrides, we investigate high-pressure phase diagram compounds that may have formed experiment, using first-principles calculations for evolutionary crystal structure prediction and superconductivity. Starting from hypothesis observed T c be realized successive heating upon a pre-formed LaH 10 phase, examine plausible ternaries lanthanum, hydrogen other elements present diamond anvil cell: boron, nitrogen, carbon, platinum, gallium, gold. We find only boron and, lesser extent, gallium form metastable superhydride-like structures can host high- superconductivity, but predicted ’s are incompatible experimental reports. Our results indicate that, while claims should reconsidered, it is very likely unknown H-rich ternary or multinary phases containing hydrogen, possibly under reported conditions, these exhibit superconducting properties comparable, even superior, those currently known hydrides.