Self consistent semi-empirical calculation of the electronic band structures of crystalline solids. Application to graphite monofluoride

Abstract

A self consistent semi-empirical LCAO method, intended primarily for the calculation of electronic band structures of crystals, is described which does not make use of zero differential overlap approximations. Thus it is possible to avoid explicit use of the density matrix, the evaluation of which for crystals requires careful averaging over the Brillouin zone, in the Hartree–Fock–Roothaan equations. Instead Mulliken gross populations are employed to adjust atomic valence state ionisation energies and lattice potentials to self-consistency. Theoretical justification of the method relies on approximations associated with Mulliken and Rudenberg.The electronic band structure and valence band density-of-states are calculated for graphite monofluoride. Good agreement is found between the results and the XPS spectrum of this compound.