OPERATOR SPECTRUM TRANSFORMATION IN HARTREE<i>–</i>FOCK AND KOHN–SHAM EQUATIONS

Abstract

The paper proposes a method for preliminary transformation of the spectrum of the equation operator both in the Hartree–Fock method and in density functional theory. This method makes it possible to solve a partial eigenvalue problem instead of the complete one, and the eigenfunctions turn out to be ordered in a way convenient for calculation. The transformation makes an old idea of grid approximation of a solution competitive in terms of computational speed as compared to widely used approaches based on basis sets methods.