Influence of surface degrees of freedom on the adsorption of Ge ad-atoms on Si(1 0 0)

The adsorption of the Ge monomer on the Si(1 0 0) surface is studied through first principles calculations based on the density-functional theory. We have observed that, for a given position of the monomer on the surface, there are many local minima which differ in the substrate local configuration of the buckling of the silicon dimers. We show that this local configuration may also play an important role for the diffusion of these ad-atoms.