Hartree–Fock study of polysulphur-nitride. I. The isolated infinite chain

Abstract
The electronic structure of the infinite chain of polysulphur-nitride (SN)x has been investigated at an ab initio Hartree–Fock level, using two basis sets previously employed to study molecular precursors and molecular subchains. The use of d orbitals turns out to be essential for stabilizing the polymer and reducing its ionicity. Nonmetallic broken-symmetry solutions are considered also, the stabilization energy in this case is quite small (0.2 eV/cell).