On the relation between the quantum scattering theory and the molecular orbital theories of chemical reactivity

摘要

The reaction amplitude lsqb;or transition (Thyphen;)hyphen;matrix elementrsqb; in the quantum scattering theory is expressed, under the several approximations, by two terms which we call here the electronichyphen;transition (E) term and the nuclearhyphen;overlap (N) term, respectively. It is shown that theEandNterms are closely related to the correlationhyphen;diagram method and the perturbative method, both of which are familiar to chemists as the qualitative MO theories of chemical reactivity. We also show that as a merit of starting with the formal theory of scattering, the nonadiabatic effects are taken into account in our derivation, naturally and systematically. This fact enables us to extend our treatment to nonadiabatic chemical reactions and photochemical reactions.