Projector augmented wave formulation of Hartree-Fock calculations of electronic structure

The projector augmented wave (PAW) formalism developed by Blochl [Phys. Rev. B 50, 17953 (1994)] has been demonstrated to be an accurate and efficient pseudopotential-like scheme for electronic-structure calculations within density-functional theory. We have extended this formalism to treat the integral-differential equations of Hartree-Fock (HF) theory, demonstrating that the PAW-HF method is able to calculate valence energies with the same accuracy as the frozen-core orbital approximation. We show that for some elements, electrons in core states provide significant contributions to the valence exchange energy and we develop schemes for incorporating their effects into the PAW-HF formalism.