AN INVESTIGATION OF THE SHAPE OF SMALL PLATINUM CLUSTERS USING THE EMBEDDED ATOM METHOD

The equilibrium shape and structure of small platinum clusters with 5-60 atoms was investigated using the embedded atom method (EAM). An analysis of the stability of the clusters with polyhedral symmetries indicated that, except at the magic number sizes, the clusters spontaneously reconstructed to more stable shapes at 0 K. Even the magic number icosahedra and cubo-octahedra were unstable upon annealing at 500 K. The clusters which reconstruct to lower energy structures appear to be highly asymmetric and irregular. Many different structures were found to have similar energies. The annealed clusters also display surface features not found in bulk platinum.