The Hartree-Fock method is successful at predicting the electronic & magnetic structures of MnS.

This is a striking result - we are able to calculate very subtle differences between the magnetic states.

A band gap is clearly evident in the density of states showing we have an insulating state (c.f. DF theory).

Calculated charges indicate that both the rocksalt and zinc blende structures of MnS are largely ionic.

The density of states show only the presence of spin-up electrons - i.e. we have a high spin state as observed experimentally.

The splittings of the eg and t2g orbitals according to crystal field theory are not observed due to subtle effects including Coulombic and exchange interactions. Don't believe everything that you're taught !!

Many thanks to my supervisor, Dr. Neil Allan, and our collaborator, Dr. Bill Mackrodt from St. Andrews.