A RIGOROUS ENERGY PARTITIONING SCHEME FOR ANALYSIS OF MOLECULAR-INTERACTIONS

A rigorous method for partitioning the molecular interaction energy in to classical electrostatic, charge-transfer, and wavefunction relaxati on contributions is proposed. The energy components, defined with quan tities central to density functional theory, are calculated with the h elp of the topological theory of atoms in molecules. Since the new sch eme does not rely on Hilbert space partitioning, it is applicable to a ny level of electronic structure theory and it yields energy component s that are true observables converging smoothly at the limit of a comp lete basis set. For this reason, the new method does not possess the d eficiencies of the previously introduced Morokuma-Kitaura and Glendeni ng-Streitwieser approaches. The results of several test calculations a re compared with those obtained with the other energy partitioning sch emes and found to exhibit superior numerical stability with respect to the quality of basis sets.