Electronic Properties and Stability of Silicon Nanoclusters Passivated by Hydrogen

The total energy, geometry and electronic spectra of nanoclusters \shm{} ($m=0\ldots11$) are calculated using the evolutionary algorithm and density functional theory (DFT). It is shown, that the features of electron spectrum, namely HOMO-LUMO gap and valence band width, correlate with cluster geometry and stability. The HOMO-LUMO gap becomes wider as the number of hydrogen atoms increases whereas the width of valence band gets lower. The widening of the band gap indicates the increasing of cluster stability which is consistent with existing data on reaction energy.