This work reports a first-principles study of the pressure-dependent superconductivity of Nb2CN, which crystallizes in a caswellsilverite-like trigonal structure (R \(\bar{3}\) m). The cohesive energy of the material was found to be − 8.39 eV per atom at 0 GPa, and it became less negative at higher pressures. The structure possesses mechanical stability, making it suitable for fabrication. In addition, the material is found to possess ultra-incompressibility in addition to exhibiting hardening and stiffening under pressure. Electronic structure calculations reveal dominant Nb-d states at the Fermi level; on the other hand, the valence band was dominated by C-p and N-p contributions. The structure possesses dynamical stability with a superconducting T \(_c\) of 9 K at ambient pressure with an electron–phonon coupling constant of \(\lambda\) = 0.589. Anisotropic Migdal–Eliashberg analysis indicates single-gap, s-wave superconductivity. Under pressure, phonon hardening enhances the electron–phonon interaction, increasing \(T_{\textrm{c}}\) to 12 K ( \(\lambda\) = 0.635) at 5 GPa and 15 K ( \(\lambda\) = 0.784) at 10 GPa. The inclusion of spin–orbit coupling (SOC) in the electronic structure and phonon spectra were found to have no effect; however, the electron–phonon coupling was found to be enhanced slightly with SOC. This work establishes Nb2CN as a pressure-enhanced, phonon-mediated superconductor.
