An ab initio Hartree-Fock study of the magnetic states of polymorphs of MnS

Periodic unrestricted Hartree-Fock calculations are shown to predict the correct low-temperature magnetic phases of alpha-MnS (AF(2)) and both cubic and hexagonal forms of beta-MnS (AF(3)). The high-spin insulating nature of MnS is also correctly predicted with local moments close to those derived from neutron scattering factors. MnS in all its forms is shown to be a largely ionic p-->d charge transfer system with a predominantly d(5) (L) under bar first ionized state.