First-principles calculations were presented that provided a detailed diffusion picture of an adsorbed Si atom on the Si(111)-(7x7) surface. Several diffusion paths for the adsorbed Si atom were established by mapping out the total energy as a function of its positions on the surface. For diffusion between the faulted and unfaulted halves, the energy barriers range from 0.96 to 1.21eV, while remarkable low-energy barriers from 0.3 to 0.7eV were discovered within the faulted and unfaulted regions.

Diffusion of an Adsorbed Si Atom on the Si(111)-(7x7) Surface. C.M.Chang, C.M.Wei: Physical Review B, 2003, 67[3], 033309 (4pp)