Electron correlation contributions to one-electron properties from functionals of the Hartree–Fock electron density

Abstract

Equations for the electron correlation contributions to one-electron properties calculated with correlation energy functionals of the Hartree–Fock density are derived. For any functional that is of an explicitly algebraic form, these contributions are limited to the occupied-virtual block of the one-electron density matrix. This deficiency results in very poor values of one-electron properties, as demonstrated by numerical examples. Implications of these observations to the future of the density functional theory (DFT)-based electronic structure methods are discussed.