First-principle study on superconductivity of metastable MoH₉ and MoH₁₂ under high pressure

In the field of hydride research, the majority of existing work has focused on the main group elements (such as alkali and alkaline earth metals) and group III_B elements (Sc, Y, and their congeners). However, there remains a significant gap in the study of high-pressure phase behavior, electronic structure modulation, and functional properties of hydrides of other transition metal groups, particularly those of groups IV_B and V_B. Systematic experimental and theoretical explorations of molybdenum-based hydrides have not been adequately conducted. This study employs first-principles calculations to systematically investigate the stability, crystal structure, electronic properties, and superconductivity of MoH₉ and MoH₁₂ under high pressure. Pmn2₁-MoH₉ remains stable within the 150-300 GPa range, with a critical temperature (T _c ) of 82.9-93.7 K at 200 GPa, which decreases with increasing pressure. Cc-MoH₁₂ is stable at 50-200 GPa, with a T _c of 60.5-67.8 K at 200 GPa pressure.