  A recently proposed approach for performing electronic-structure calculations
on crystalline insulators in terms of localized orthogonal orbitals is applied
to the oxides of lithium and sodium, Li2O and Na2O. Cohesive energies, lattice
constants and bulk moduli of the aforementioned systems are determined at the
Hartree-Fock level, and the corresponding values are shown to be in excellent
agreement with the values obtained by a traditional Bloch-orbital-based
Hartree-Fock approach. The present Wannier-function-based approach is expected
to be advantageous in the treatment of electron-correlation effects in an
infinite solid by conventional quantum-chemical methods.
