Structures of small sulfur clusters Sn (n=2∼8) from Langevin molecular dynamics methods

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 S-n ( n = 2 similar to 8). It is found that the ground state structures of S-3, S-4, S-5, S-6, S-7 and S-8 are C-2v, D-2h, envelope-shaped C-s, D-3d(or boat-shaped C-2v), a chair-shaped C-s and D-4d 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.