New ?localized orbitals? appropriate for post-Hartree?Fock calculations

Abstract

rnIn this work, we propose a new orbital set based on density matrices of subsystems. Most of the resultant orbitals are localized in the subsystems and resemble the natural orbitals of the subsystems. Correlation between two electrons, each in a distant localized orbital, should be small and the corresponding configurations can be neglected in a calculation Test calculations are performed on hexatriene and the usefulness of these orbitals is shown. 0