intrinsic barrier
The Gibbs energy of activation (Math - text) in the limiting case where Math - ei, i.e. when the effect of thermodynamic driving force is eliminated. According to the Marcus equation, the intrinsic barrier is related to the reorganization energy, Math - text, of the reaction by the equation:
Math - e
Source:
PAC, 1994, 66, 1077 (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1126