Structure of small hydrogenated silicon clusters: global search of low-energy states

Quantum-chemical calculations of the SinHm clusters structure are carried out for n=6–16 and wide range of hydrogen content. The low-energy states are found using a procedure which allows to construct a wide row of qualitatively different structures and reveals a number of local minima for each structural type. General structural peculiarities of SinHm, which appear for the clusters containing more than 12 silicon atoms, are discussed.