The possible geometrical structures and relative stability of silicon-sulfur clusters [(SiS~2)~nS]^+(n=1～4) are explored by means of density functional theory (DFT) quantum chemical calculations (B3LYP/6-31G*). The effects of polarization functions and electron correlation are included in these calculations. The electronic structure and vibrational spectrum of the most stable geometrical structure of [(SiS~2)~nS]^+ are analyzed by the same method. As the result, the regularity of the [(SiS~2)~nS]^+ cluster growing is predicted, and the calculation may predict the mechanism of the [ (SiS~2)~nS]^+ cluster forming.

Key words: SILICON COMPOUNDS, SULFUR COMPOUNDS, ELECTRONIC STRUCTURE, VIBRATIONAL SPECTRUM