By combining a genetic algorithm for crystal structure prediction with first-principles calculations, both thermodynamically stable and metastable phases in the V-Sn binary system are systematically investigated. The experimentally synthesized A15-type ${\mathrm{V}}_3\mathrm{Sn}$ and $\mathrm{VS}{\mathrm{n}}_2$ are successfully reproduced, validating the reliability of the structure search. In addition, new stoichiometric compounds ${\mathrm{V}}_7\mathrm{Sn}, {\mathrm{V}}_{13}\mathrm{S}{\mathrm{n}}_3$, and ${\mathrm{V}}_2\mathrm{Sn}$ are predicted to be thermodynamically stable at ambient pressure. The superconducting critical temperature ($T_{\mathrm{c}}$) of V-rich compounds is found to increase with vanadium content, with ${\mathrm{V}}_7\mathrm{Sn}$ and ${\mathrm{V}}_{13}\mathrm{S}{\mathrm{n}}_3$ exhibiting $T_{\mathrm{c}}$ values of 23.22 and 18.55 K, respectively—significantly higher than that of the A15-type ${\mathrm{V}}_3\mathrm{Sn}$. In these superconductors, the V-$3d$ orbitals dominate the electronic states at the Fermi level, while V-dominated vibrational modes contribute more than 50% to the total electron-phonon coupling constant. These findings provide valuable insights into the superconducting behavior of non-A15 compounds within A15-related binary systems.

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• Electron-phonon coupling
• Superconductivity
• Inorganic compounds
• Density functional theory