Route to high-Tc superconductivity via CH4-intercalated H3 S hydride perovskites

While exploring potential superconductors in the C-S-H ternary system using first-principles crystal structure prediction methods, we uncovered a class of hydride perovskites based on the intercalation of methane into an H3S framework. These intriguing H3S-CH4 structures emerge as metastable at ∼100 GPa. Electron-phonon coupling calculations indicate that phases with CSH7 stoichiometry are potential superconductors with Tc values ranging from 100 K to 190 K at megabar pressures. The results are expected to guide the experimental search for new high-Tc superconductors, including those stable at lower pressures than previously documented superconducting hydrides such as H3S and LaH10.