Prediction of BaBiO₃-like superconducting perovskites in K-doped SrAsO₃

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Using first-principles calculations, we predict a new perovskite compound SrAsO₃. The undoped cubic phase has pronounced soft-phonon instabilities, which are gradually suppressed upon K doping the Sr site. The cubic phase becomes dynamically stable for K-doping levels above approximately 60%, and the stabilized K-doped phases are metallic with predicted conventional phonon mediated superconductivity. Moreover, the inclusion of nonlocal exchange interactions broadens the electronic bandwidth, enhances the electron-phonon coupling (EPC) strength, and increases the superconducting transition temperature (Tc) of these doped compounds. In particular, the HSE06 hybrid exchange-correlation functional corrected EPC constant λ reaches 1.41 for Sr₀.₄K₀.₆AsO₃, corresponding to a predicted Tc of 44.3 K. These results suggest that SrAsO₃ is a BaBiO₃-like superconducting perovskite driven by strong electron-phonon coupling.