radiative lifetime, \(\tau_{0}\)

Also contains definition of: natural lifetime
https://doi.org/10.1351/goldbook.R05064
@[email protected] of an excited molecular entity in the absence of radiationless transitions. The reciprocal of the first-order @[email protected] for the radiative step, or the reciprocal of the sum of these rate constants if there is more than one such step. The equivalent term, natural lifetime, is discouraged.
Notes:
  1. Approximate expressions exist relating \(\tau_{0}\) to the @[email protected] of the emitting transition.
  2. The subscript \(0\) is used in this definition, whereas the superscript \(0\) is used to indicate a non-quenched @[email protected] in the Stern-Volmer kinetic relationships.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 411 [Terms] [Paper]