resonance energy

https://doi.org/10.1351/goldbook.R05333
The difference in potential energy between the actual @M03986@ and the @C01309@ of lowest potential energy. The @R05326@ energy cannot be measured, but only estimated, since contributing structures are not observable molecular entities.
See:
contributing structure
,
molecular entity
,
resonance
Source:
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1161 [Terms] [Paper]