I propose a hypothetical hydrogen-rich bimetallic compound, c-(Hf₀.₅Ta₀.₅)H₁₀, featuring a cubic clathrate crystal structure with space group Fm-3̅m, isostructural to the well-known high-pressure superconductor LaH₁₀. By combining heavy transition metals (hafnium and tantalum) with a dense hydrogen sublattice, this material is designed to generate strong internal chemical pressure, potentially stabilizing a highly compressed hydrogen network at or near ambient pressure. Using established theoretical frameworks for phonon-mediated superconductivity, including the McMillan–Allen–Dynes formula and isotropic Eliashberg theory, I estimate a superconducting critical temperature approaching the room-temperature regime, contingent on metastable structural retention.
Giustino Travaglini (Thu,) studied this question.