https://doi.org/10.1351/goldbook.I03134
If \(E_{\text{a,1}}\) and \(E_{\text{a,- 1}}\) are the @[email protected] for a reaction in forward and reverse directions, the lesser of the two is sometimes called the intrinsic @[email protected] energy. It is the @[email protected] energy for the reaction in the exothermic direction.