A model description of intermolecular electron transfer and intramolecular electron transfer (and related to it methyl transfer) reactions in organic solids are discussed. As a first step towards quantitative modeling of the reactions we construct potential energy surface in the phonon normal coordinates space. A role of coupling of the transferred electron to intramolecular vibrations and excitons which determine dielectric properties of the crystal is stressed. Transformations "neutral-ionic" in TTF-Chloranil and zwitterion formation in Methyl p-Dimethylaminobenzenesulfonate are discussed as examples.