Correlation factor approach to the correlation energy functional

A global survey of the correlation factor energy functionals and its application to atomic and molecular properties is made. Its performances are compared with those of the density functional theory (DFT) correlation energy functionals, and some interesting conclusions from previous publications are reinforced here; namely, after removing the one-Slater-determinant hypothesis from the Kohn–Sham method, all DFT correlation functionals are able to provide reasonable results in any circumstance, with an additional restriction, for systems having a quasi-degenerate wave function, the DFT correlation functionals must depend explicitly on the on-top density. Acknowledgement.This work has been done under the support of the Spain DGICYT, project n⁰ BQU2001-0883.