A study was made of the diffusion and rotation of Pt nanoclusters on graphite. Using molecular dynamics simulations, it was shown that the supported Pt clusters had two types of bottom layer: an hexagonal lattice or a rectangular lattice. The diffusion rate of the Pt clusters depended mainly upon the type of bottom layer. This was explained by periodic lattice-matching between the bottom layer and the graphite. In addition to lateral diffusion, Pt clusters having a rectangular or mixed lattice tended to rotate or wag on the z-axis. By using the rotation rates and total movements of all atoms, it was shown that the rotation of a Pt cluster could be induced by the difference in the diffusion rates for the different types of bottom layer.

Molecular Dynamics Simulations of the Diffusion and Rotation of Pt Nanoclusters Supported on Graphite. Ryu, J.H., Seo, D.H., Kim, D.H., Lee, H.M.: Physical Chemistry Chemical Physics, 2009, 11[3], 503-7