First principles study of mechanical, thermal, electronic, optical and superconducting properties of C40-type germanide-based MGe2 (M = V, Nb and Ta)

•A comprehensive theoretical study on MGe2 (M = V, Nb, and Ta) compounds using DFT calculations.•The compounds are brittle and elastically anisotropic in nature.•The estimated hardness values of MGe2 (M = V, Nb and Ta) are found to be 16.95, 14.96 and 19.6 GPa, respectively.•The NbGe2 and TaGe2 compound could be categorized as a type-2 superconductor.•The compounds can be used as potential coating materials in some specific sectors. Non-centrosymmetric germanide-based superconductors have recently attracted particular attention because of their unconventional physical properties. In the present study, we comprehensively investigated the structural and hitherto unexplored electronic, optical, mechanical, thermal, and superconducting state properties of germanide-based superconductors, MGe2 (M = V, Nb, and Ta), using the density functional theory. The obtained lattice parameters and accordingly the volume of the unit cells agree very well with the earlier reported values, indicating the high reliability of the physical properties studied. All the compounds studied herein are dynamically and mechanically stable. The compounds are brittle (ranked: NbGe2