PARTITIONING OF THE ORBITAL OVERLAP MATRIX AND THE LOCALIZATION CRITERIA

A new molecular orbital localization procedure is proposed. The approach is based on partitioning of the overlap matrix into atomic contributions in accordance with Bader's topological theory of atoms in molecules. The new procedure has several advantages over other schemes. It preserves the sigma/pi-separability in planar systems and allows for a straightforward interpretation of the localized orbitals in terms of their localization indices and atomic occupancies. The new procedure is tested on the H2O, LiF, N2, CO, BH3.CO and Li2 molecules.