Energy Decomposition Analysis of Molecular Interactions

Abstract

In the theoretical study of molecular interactions, ab initio molecular orbital calculations have been applied successfully in predicting the binding energy and the geometry of intermolecular complexes.1–3 In what is called the supermolecule method the entire complex is considered as a supermolecule, and the calculated energy difference between the supermolecule and the monomers is the binding energy. In order to facilitate an interpretation of the results, methods have been proposed4–7 to decompose the interaction energy into physically meaningful energy components such as electrostatic, polarization, charge transfer, and exchange energies. Analyses of many molecular complexes along these lines have provided the basis for elucidating the origin or the nature of various molecular interactions such as hydrogen bonds and electron donor-acceptor complexes.