Abstract: A first-principles density-functional theory method, i.e. the finite-difference pseudopotential density-functional theory in real space and Langevin molecular dynamics annealing technique (PDFMD),is introduced to describe the structures and properties of small sulfur clusters Sn(n=2～8). It is found that the ground state structures of S3, S4, S5, S6, S7 and S8 are C2v, D2h, envelope-shaped Cs, D3d (or boat-shaped C2v), a chair-shaped Cs and D4d symmetry structures, respectively, which are in good agreement with experiment. It is shown that the more the number of atom in the cluster, the more stable it is for small sulfur clusters.

Key words: Pseudopotential density-functional theory, Real space, Langevin molecular dynamics annealing technique, Small sulfur clusters