reorganization energy in electron transfer

Gibbs energy dissipated when a system that has undergone 'vertical' electron transfer (i.e., electron transfer obeying the Franck–Condon principle) relaxes to the equilibrium state for its new charge distribution. Commonly the total reorganization energy ( $λ$ ) is written as the sum of an inner contribution ( $λ in$ ) and an outer contribution ( $λ out$ ) attributed to nuclear reorganizations of the redox partners and their environment (solvent), respectively.

Note:

Approximations have been proposed to calculate the value of $λ out$ taking into account the 'relative permittivity' of the solvent.

Source:

PAC, 2007, 79, 293 (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 414