Term: delocalization energy (DE)
https://doi.org/10.1351/goldbook.DT07020

Definition:
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 molecular orbital theory.

Related Terms:
1) molecular orbital (http://doi.org/10.1351/goldbook.M03996).

Source: PAC, 1999, 71, 1919. 'Glossary of terms used in theoretical organic chemistry' on page 1933 (https://doi.org/10.1351/pac199971101919)

Citation: 'delocalization energy (DE)' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.DT07020

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