Chemical Bonding in the N₂ Molecule and the Role of the Quantum Mechanical Interference Effect

The chemical bond in the N₂ molecule is analyzed from the perspective of the quantum mechanical interference effect by means of the recently developed generalized product function energy partitioning (GPF-EP) scheme. The analysis is carried out at the GVB-PP and SC levels, which constitute interpretable independent particle models, while ensuring the correct dissociation behavior for the molecule. The results suggest that some current ideas concerning the bond in the N₂ molecule should be revised. It is shown that, in the absence of the interference effect, there is no chemical bond in the N₂ molecule. The influence of the basis set on the energy partitioning is also evaluated. The interference contributions to the energy are substantially less sensitive to the choice of the basis set than the reference energy, making the investigation of the relative importance of inteference effects in larger systems feasible.