The high-pressure superconductivity of SbH and SbH₄

At present, systematic research on SbH_x is still relatively limited, and its high-pressure phase structure, electronic properties, and electron-phonon coupling mechanism have not been fully revealed. Based on first-principles calculations, this paper respectively studies the structure, electronic properties, superconducting transition temperature T_C, and electron-phonon coupling of SbH and SbH₄. By calculating their Mulliken bond charge analysis and electron density difference, it was known that the bonding between Sb atoms and H atoms in SbH and SbH₄ is different. The electron-phonon coupling and superconducting properties under a stable structure were further calculated. The electron-phonon coupling constant λ of the Pnma phase SbH at 200 GPa is 0.52, and the predicted superconducting transition temperature T_C is 10.7 K. In addition, the T_C of SbH₄ in the P6₃/mmc phase at 150 GPa is approximately 99 K. COMPUTATIONAL METHOD: All calculations are based on density functional theory (DFT), which is implemented in the CASTEP software and the Quantum Espresso (QE) open-source package. The pseudo-potential is adopted by the norm-conserving, and in the local generalized gradient approximation (GGA), the Perdew-Burke-Ernzerhof method employs the exchange-correlation function.