A modified form of the Stillinger-Weber potential was used to obtain the adsorption sites of a silicon atom on fully relaxed Si(001)-2x1 surfaces. The barriers between sites were found, and used to estimate the hopping rates from site to site. It was concluded that the direction of easy diffusion was parallel and to the side of the dimer rows. The effective activation energy (0.33eV) for the resultant quasi one-dimensional motion was compared with experimental estimates. The results explained the appearance of regular island growth at high temperatures as well as low-temperature diluted-dimer growth.

Diffusion of a Si Atom on the Si(001)-2x1 Surface: a Monte Carlo Study. C.P.Toh, C.K.Ong: Physical Review B, 1992, 45[19], 11120-5