Molecular dynamics simulations revealed a new outlook on diffusion dynamics on the surface of amorphous silicon. The primary transport mechanism differed substantially from that observed on crystalline surfaces, in which small numbers of highly mobile adatoms or vacancies formed and then diffused over substantial distances. Instead, diffusion took place via large numbers of single atoms or dimers that moved by about one atomic diameter and were associated with highly strained rings of four atoms.

Diffusion Mechanisms on Amorphous Silicon Surfaces. A.S.Dalton, Y.V.Kondratenko, E.G.Seebauer: Chemical Engineering Science, 2010, 65[6], 2172-6