Nonorthogonal tight-binding molecular-dynamics study of silicon clusters

A universal-parameter tight-binding molecular-dynamics technique is detailed and used to obtain equilibrium geometries, energies, and vibrational frequencies of small silicon clusters. With this scheme there is complete agreement with ab initio results for the lowest-energy structures of clusters of size up to N=10 (for which ab initio results are available). The frequency analysis shows that it is important to include the effects of nonorthogonality in order to obtain reasonable estimates even for small clusters.