High-pressure superconductivity in hexagonal CaSH3 with a nonclathrate molecular hydrogen structure.
Understanding the interplay between pressure-driven Fermi surface electronic states and phonon hardening is essential for exploring high-temperature superconducting materials. In this study, using first-principles structure searches, we identify two thermodynamically stable ternary Ca-S-H phases at 200 GPa: P6̄m2 CaSH3...