A molecular dynamics study was made of the static and dynamic behavior of large Lennard-Jones clusters on a crystalline surface. It was found that large clusters could diffuse rapidly; as observed experimentally. The role of the mismatch, between the lattice parameters of the cluster and of the substrate, was emphasized in order to explain the diffusion of the cluster. This diffusion could be described as being a Brownian motion that was induced by internal vibrations of the cluster and/or vibrations of the substrate. It was noted that such a mechanism had not previously been considered for cluster diffusion.

P.Deltour, J.L.Barrat, P.Jensen: Physical Review Letters, 1997, 78[24], 4597-601