GENERALIZATION OF THE COLLE-SALVETTI CORRELATION-ENERGY METHOD TO A MANY-DETERMINANT WAVE-FUNCTION

The Colle-Salvetti method for calculating the correlation energy [Theor. Chim. Acta 37, 329 (1975)] is generalized to treat cases in which the reference function not a Hartree-Fock one, but a many-determinant wave function. Through calculations on atoms and diatomic molecules it is shown that this generalized approach gives the "experimental," non-relativistic electronic energy at a millihartree level of accuracy also for internuclear distances far from the equilibrium positions. © 1990 American Institute of Physics.