An indirect method of determination of
excited state equilibria, such as

values, based on
ground state thermodynamics and electronic transition energies. This cycle considers only the
difference in molar
enthalpy change
(
) of reaction of ground and excited states, neglecting the difference in molar
entropy change of reaction of those states
(
).Source:
PAC, 1996, 68, 2223
(Glossary of terms used in photochemistry (IUPAC Recommendations 1996))
on page 2243