Extensive first-principles calculations were performed in order to study the binding and diffusion of a Si ad-dimer on the (001) surface. A correlated piece-wise diffusion pathway was found to be favoured by the Si ad-dimer on (001), with an energy barrier of 1.02eV.

Correlated Piece-Wise Diffusion of a Ge Ad-Dimer on the Si(001) Surface. Z.Y.Lu, C.Z.Wang, K.M.Ho: Physical Review B, 2000, 62[12], 8104-7