delocalization energy (DE)

https://doi.org/10.1351/goldbook.DT07020
The difference between the actual π-electron energy of a molecular entity and the π-electron energy of a hypothetical species with a localized form of the π-electron system. These energies are normally evaluated within Hückel @M03996@ theory.
Source:
PAC, 1999, 71, 1919. (Glossary of terms used in theoretical organic chemistry) on page 1933 [Terms] [Paper]