The mol. interaction energy orthogonality decomposition method is based on expanding the wave function of combined reactants A and B into a series of selected electronic configuration wave functions of the product AB. A quant. estimate of the relative importance of s and p bond in A-B bond is obtained. As an example, the orthogonality decomposition of the reaction energy of BH3 and CO forming borane carbonyl is carried out to illustrate the application of this method.

Key words: CHEMICAL REACTION, MOLECULAR ORBITAL THEORY, ENERGY DECOMPOSITION METHOD