The various binding sites and saddle points for an adatom on the (100) 2 x 1 symmetrical reconstructed surface were obtained by using a self-consistent semi-empirical method. This was done by minimizing the total energy, at each selected position on the surface, with respect to the adatom height and to the positions of its nearest-neighbor atoms. The diffusion of an adatom on the surface was found to be anisotropic. The preferred motion occurred along a zig-zag path, which was parallel to the dimer rows, with an activation energy of about 0.63eV. This value was consistent with published theoretical calculations and experimental estimates.

C.K.Ong: Journal of the Physics and Chemistry of Solids, 1993, 54[2], 183-5