Hartree-Fock LAPW approach to the electronic properties of periodic systems

We present a scheme for calculating the (spin-unrestricted) Hartree-Fock (HF) band structure of periodic solids that uses the accurate linearized-augmented-plane-wave basis set. In contrast with linear-combination-of-atomic-orbitals-like schemes, the convergence of the variational HF results can be easily monitored, and the cumbersome evaluation of multicenter integrals is avoided. Potentials and charge densities are evaluated without any shape approximation, and the singularity due to the long-range nature of the Coulomb potential is handled in reciprocal space. All the elements of the Periodic Table can be equally treated, and the relativistic effects for heavy elements are included as in the standard local-density-approximation case. The method is tested on silicon and diamond, where recent HF calculations are available for comparison. The diagonal Coulomb-hole-plus-screened-exchange approximation can also be implemented with little additional computational effort.