Binding sites and diffusion pathways of Si adatoms on a c(4x2) reconstructed Si(001) surface were investigated using a tight-binding method with an environment-dependent silicon potential in conjunction with ab initio calculations using the Car–Parrinello method. A diffusion pathway along the trough-edge, driven by dimer flipping, was found having a barrier of 0.74eV. This was comparable to the 0.68eV necessary along the top of the dimer rows.

Dimer-Flipping-Assisted Diffusion on a Si(001) Surface. Zi, J., Min, B.J., Lu, Y., Wang, C.Z., Ho, K.M.: Applied Physics Letters, 2000, 77, 4184