Extensive first-principles calculations were performed in order to study the binding and diffusion of a Ge ad-dimer on the (001) Si surface. The diffusion of a Ge ad-dimer along the lowest-energy barrier pathway was found to be piece-wise, but strongly correlated, with an energy barrier of 0.77eV. The prediction was in excellent agreement with experimental data.

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