Ab initio SCF nonlinear pair population analysis. A new means of detection and localization of multicenter bonding

The nonlinear population analysis recently formulated at the level of semiempirical MO methods was generalized so as to be applicable to the ab initio SCF closed shell level of theory. The method provides a new, efficient means of visualization of molecular structure especially for molecules with complex bonding patterns such as multicenter bonding. The approach was applied to the visualization of bonding in several simple boranes like B2H6, B4H10, B5H9, and B5H11. In all cases the approach was able to detect and to correctly localize the three-center bonds in these molecules.