Band Structure of Diamond

A calculation of the valence and conduction bands of diamond has been carried out, using a set of eight localized bond orbitals, four bonding and four antibonding, made up from simple tetrahedral orbitals. Bloch functions have been set up in the usual way and overlap among them neglected. Interactions up to and including third parallel nearest neighbour bonds have been taken into account. A Hartree-Fock type of potential has been used, with inclusion of exchange. All one and two centre integrals have been calculated exactly, three and four centre integrals have been approximated.