Energy Density Distribution in Bridged Cobalt Complexes

In the theory of atoms in molecules (AIM), the charge density is usually a suitable tool for bonding analyses. However, problems arise in some cases. So, no direct Co−Co bond is found in Co2(CO)8. It is shown that the energy density gives deeper insight into the bonding properties. This is demonstrated for Co2(CO)8, Co4(CO)12, and Co2(CO)6(InMe)2. The strategy is not restricted to transition metal compounds; it should be useful to identify any weak bonding or antibonding interactions.