Atomic orbital participation on a chemical bond through a binding energy partitioning scheme

摘要

The participation of atomic orbitals in bond formation is presented here in terms of energy contributions. This approach is based on partition of inter-atomic energy in its components: resonance ?, electron-electron repulsion(J), attractive electron-nucleus (V), exchange (K), and nucleus-nucleus-nucleus repulsion (N) for pairs of interacting orbitals. In a similar way, changes of intra-atomic energy per atomic orbital were also considered. The proposed partition model allows a detailed analysis of the contribution of each atomic orbital in the formation of the bond. It is possible to distinguish the energetic changes or rearrangements that occur on each atom (monoatomic terms) and those that are associated to direct inter-atomic orbital-orbital interactions (diatomic terms). Thus, diatomic binding energy (DBE) is expressed as a sum of atomic orbital binding energies (AOBEs). A complementary picture is also introduced by analyzing inter-atomic electron-atom bonding interactions. To illustrate those models, and analysis of atomic orbital participation in Ni-Ni and Ni-O bonds of diatomic molecules and in Ni_5-O cluster were performed by using a parametric method.