Orthogonal polynomial projectors for the projector augmented wave method of electronic structure calculations

Abstract

The projector augmented wave (PAW) method for electronic structure calculations developed by Bl\ochl [Phys. Rev. B 50, 17 953 (1994)] has been very successfully used for density functional studies. It has the numerical advantages of pseudopotential techniques while retaining the physics of all-electron formalisms. We describe a method for generating the set of atom-centered projector and basis functions that are needed for the PAW method. This scheme chooses the shapes of the projector functions from a set of orthogonal polynomials multiplied by a localizing weight factor. Numerical benefits of the scheme result from having direct control of the shape of the projector functions and from the use of a simple repulsive local potential term to eliminate ``ghost state'' problems, which can plague calculations of this kind. Electronic density of states results are presented for the mineral powellite $({\mathrm{CaMoO}}_{4}).$