Incorporation of electronically nonadiabatic effects into bimolecular reactive systems. I. Theory

Electronic nonadiabatic interactions are smoothly incorporated into existing exact quantum mechanical methods for treating reactive (or nonreactive) bimolecular systems. A known method for treating reactive systems on a single surface is first given, and then it is shown how to proceed to include electronically nonadiabatic effects. The unexpected result is that the final equations are very similar to those of the one surface case and, therefore, existing methods for treating the single surface case can be directly applied to the many surface case. For the sake of simplicity the study is performed in the frame of the collinear model, but the treatment can easily be extended to three dimensional systems.