A modified form of the Stillinger-Weber potential was used to determine the adsorption sites of a Si atom on the fully-relaxed 2 x 1 (001) surface. The barriers between sites were also found, and these were used to estimate the hopping rates from site to site. It was concluded that the direction of easy diffusion was parallel to, and to one side of, the dimer rows. The effective activation energy for the resultant quasi one-dimensional motion was about 0.33eV. The results also explained the appearance of regular island growth at high temperatures, and so-called low-temperature diluted-dimer growth.

C.P.Toh, C.K.Ong: Physical Review B, 1992, 45[19], 11120-5