Correspondingly, the electron density in the dx2-y2 orbital in Gd decreases as Te atoms being more electronegative pulls electron density from Gd. Now, H atom approaching the surface from the z-direction interacts by its s-orbital with the orbitals of the surface atoms having more zdirected orientation (dxz, dyz, dz2). This in turn proves the superiority of GdTe bimetallic surface over Gd surface.