A modified coupled pair functional approach

Abstract
A modified coupled pair functional (MCPF) method is presented that dramatically improves properties for cases where the Hartree–Fock reference configuration is not a good zeroth-order description of the wave function. This new methodology is compared to singles-plus-doubles configuration interaction and the CPF method of Ahlrichs et al. for the ground states of NiH, CuH, and ZnH.