Optimized Ultrasoft Pseudopotentials

Abstract

Optimization of ultrasoft pseudopotentials is discussed from two points, i.e. (1) parametrization and function forms ofpseudo-wavefunctions and local part of pseudopotentials, and (2) pseudization of augmentation charge.The cutoff energy for the Fourier components of the non-local partof the ultrasoft pseudopotential should be carefully chosen, because calculated cohesive energy often changes drastically with a change of the cutoff energy for the non-local part. Proposed optimization for the pseudized augmentation charge canefficiently make short wavelength components vanish. Examples of pseudopotentials are shown for a carbon atom. Charge density and cohesive energy are exemplified for diamond.