Ductile high-temperature superconductors are essential for engineering applications such as superconducting tapes and wires. However, materials that simultaneously exhibit mechanical ductility and a superconducting transition temperature ($T_c$) above liquid nitrogen temperature remain scarce. In this study, we start with the experimentally reported ${\mathrm{Al}}_7\mathrm{Mg}$ alloy and investigate the structures, electron-phonon coupling (EPC), and superconducting properties of various ${\mathrm{Al}}_7{\mathrm{MgH}}_2$ configurations through first-principles calculations combined with statistical methods. Statistical analysis reveals that the percentage contribution of H density of states at the Fermi level ($E_F$) and the H local space are two factors determining superconductivity. While the hydrogen occupation site has a negligible effect on the electronic structure, it significantly alters the phonon spectra. Specifically, the intrinsic vibrational modes of H are primarily associated with phonon frequencies, whereas the local chemical environment of H strongly influences EPC through phonon spectra softening or hardening, as demonstrated through our analysis of H phonon splitting and vibrational mode visualization. The predicted ${\mathrm{Al}}_7{\mathrm{MgH}}_2$ crystal can sustain superconductivity up to 64 K at ambient pressure while exhibiting excellent ductility comparable to that of Al and AlMg alloys. Our results show that AlMg-based hydrides may bridge the gap in the absence of ductile superconductors near the liquid-nitrogen temperature and offer a different perspective on how interstitial hydrogen configurations affect conventional $s$-wave superconductivity.

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• Chemical bonding
• Ductility
• Electronic structure
• Structural properties
• Superconductivity
• Hydrides
• Superconductors
• First-principles calculations
• Methods in superconductivity