Ground state geometries and vibrational spectra of small hydrogenated silicon clusters using nonorthogonal tight-binding molecular dynamics

We report a systematic study of ground state structures, vibrational spectra, cohesive energies and HOMO-LUMO gaps of small SinHm clusters (n = 1,2 and m = 1-6) and their deuterated derivatives based on the nonorthogonal tight-binding molecular dynamics scheme. The ground state structures have been obtained by using simulated annealing. The bond lengths, bond angles and the frequencies of normal modes are found to be in good agreement with available experimental data and ab initio calculations. Our calculation of cohesive energies indicate SiH2 to be more stable than SiH3 or SiH and Si2H4, more stable than Si2H3 or Si2H5.