However, low stability of the intermediate on Te atom of (110) surface with adsorption energy 1.78 eV also decreases the reactivity of GdTe. Therefore, considering all possible different adsorption sites, H* is optimally stable on Gd atom of (100) plane having free energy of hydrogen adsorption, ∆G = 0.06 eV. This outperforms Platinum (Pt), which otherwise showed prominent capability for HER with ∆G = -0.09 eV. Similarly, the Gd atoms in (110) plane and corner site of (211) plane have substantial potential for HER with ∆G = 0.14 eV and 0.21 eV, respectively. Further, according to calculated overall surface activities, (100) plane shows best potential for HER reaction followed by (110), ( ) and ( ) surface. Eventually this ensures uninterrupted formation of large number of H2 as (100) plane has lowest surface energy of 0.02 eV/Å 2 .