First-principles local-orbital density-functional study of Al clusters

We report ab initio molecular-dynamics simulations of small aluminum clusters, Aln of n=2-6 and 12, 13, 55, and 147, using the density-functional, local-orbital method of Sankey. Equilibrium structures and total energies were calculated and compared with experiment and the predictions of other calculations. The minimum energy structure of Al13 and Al55 are found to be distorted icosahedrons, whereas that of Al147 appears to be a slightly distorted cubo-octahedron. The vibrational density of states was calculated for most of these clusters. We also performed embedded-atom method calculations for Al13, Al55, and Al147 and compared these calculations to the ab initio calculations.