Theoretical study of silicon-sulfur clusters (SiS2)(n)(-) (n=1-6)

The possible geometrical structures and relative stability of silicon-sulfu r clusters (SiS2) (n = 1-6) are explored by means of density functional the ory (DFT) quantum chemical calculations. We also compare DET with second-or der Moller-Plesset (MP2) and Hartree-Fock (HF) methods. The effects of pola rization functions, diffuse functions, and electron correlation are include d in MP2 and B3LYP quantum chemical calculations, and B3LYP is effective in larger cluster structure optimization, so we can conclude that the DFT app roach is useful in establishing trends. The electronic structures and vibra tional spectra of the most stable geometrical structures of (SiS2)(n)(-) ar e analyzed by B3LYP. As a result, the regularity of the (SiS2)(n)(-) cluste r growing is obtained, and the calculation may predict the formation mechan ism of the (SiS2)(n)(-) cluster. (C) 2001 John Wiley & Sons, Inc.