  We propose an analytical method for understanding the problem of long range
electron transfer reaction in solution, modeled by a particle undergoing
diffusive motion under the influence of many potentials which are involved
(donor - bridge - acceptor) in the process. The coupling between these
potentials are assumed to be represented by Dirac Delta functions. The
diffusive motion in this paper is represented by the Smoluchowski equation. Our
solution requires the knowledge of the Laplace transform of the Green's
function for the motion in all the uncoupled potentials.
