An indirect method of determination of @[email protected] equilibria, such as \(\text{p}K^{\text{*,a}}\) values, based on @[email protected] thermodynamics and electronic transition energies. This cycle considers only the difference in molar @[email protected] change (\(\Delta \Delta H\)) of reaction of ground and excited states, neglecting the difference in molar @[email protected] change of reaction of those states (\(\Delta \Delta S\)).