  An ab initio Hartree-Fock approach aimed at directly obtaining the localized
orthogonal orbitals (Wannier functions) of a crystalline insulator is described
in detail. The method is used to perform all-electron calculations on the
ground states of crystalline lithium fluoride and lithium chloride, without the
use of any pseudo or model potentials. Quantities such as total energy, x-ray
structure factors and Compton profiles obtained using the localized
Hartree-Fock orbitals are shown to be in excellent agreement with the
corresponding quantities calculated using the conventional Bloch-orbital based
Hartree-Fock approach. Localization characteristics of these orbitals are also
discussed in detail.
