How can we calculate the lifetime of fluorescence(S1) AND phosphorescence(T1)?
Lifetimes are a consequence of competitive processes and in general are not easily calculated. The minimum one can do is to calculate the radiative rate (from the singlet state) on the basis of Einstein’s expression, as modified by Strickler and Berg. To estimate the fluorescence lifetime, one would need to know the rates of competing processes (e.g., internal conversion, intersystem crossing).
