The Schrodinger equation for strongly interacting electron-transfer systems is described, the eigenvalues depending on a dielectric polarization function P(r) for the medium, on the internal coordinates q, and, when the electron transfer is coupled to a dissociation, on a generalized coordinate Q. A choice of the reaction coordinate for the variation of P(r), q, and Q, so as to reach the saddle-point, and the calculation of the free energy of activation are described. The question of suitable data on the solvent dependence of strong-overlap systems is also considered.