internal conversion

https://doi.org/10.1351/goldbook.I03102
A photophysical process. An isoenenergetic @R05057@ between two electronic states of the same multiplicity. When the transition results in a vibrationally excited molecular entity in the lower @ET07026@, this usually undergoes @D01528@ to its lowest vibrational level, provided the final state is not @U06569@ to @D01801@.
Source:
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2248 [Terms] [Paper]
See also:
Orange Book, 2nd ed., p. 187 [Terms]