Basic adatom self-diffusion mechanisms on (100) surfaces were considered on the basis of ab initio calculations. It was shown that the local-density approximation and the generalized gradient approximation yielded similar results; provided that the lattice constant was the same. These results were analyzed in terms of diffusion barriers as well as electronic structures. It was also shown that the diffusion barrier for the exchange process was significantly lowered when atomic relaxations were fully taken into account by using the nudged elastic band algorithm for finding the transition state.

Self-Diffusion on FCC (100) Metal Surfaces - Comparison of Different Approximations. T.Fordell, P.Salo, M.Alatalo: Physical Review B, 2002, 65[23], 233408 (4pp)