Theoretical Predictions of Superconducting Properties of Ternary Hydrides Under Pressure

When studying pressure-induced superconductivity, hydrogen stands out over other elements. Several binary alkaline and rare earth metal hydrides that assume hydrogenic clathrate systems have been predicted to posess high critical temperatures. Computational results from a ternary hydride incorporating lithium and magnesium suggested a critical temperature far above room temperature, but other mixed alkali/alkaline earth metal ternary hydrides are unexplored. Utilizing the XtalOpt evolutionary algorithm for crystal structure prediction novel superconducting ternary hydrides were discovered at experimentally attainable pressures. These systems were investigated using first-principles calculations, elucidating electronic structure, stability, and additional properties.