On the physical meaning of bond indices from the population analysis of higher order densities

In this study, the physical meaning and mutual relations of multicenter bond indices arising from various population analysis schemes is analyzed and discussed. The reported relations were numerically tested at ab initio SCF level on a series of molecules involving the representatives of systems with classical two-center two-electron (2c-2e) bonds as well as three-center two-electron (3c-2e) and three-center four-electron (3c-4e) bonds. The results show that the generalized population analyses are very suitable tools for detecting the presence and localization of multicenter bonding in molecules.