Figure 6.

(a) Diabatic potential energy curves corresponding to the two localized diabatic electron transfer states I and II and the corresponding proton vibrational wavefunctions ${\varphi }_{\mu }^{(\text{I})}$ (blue) and ${\varphi }_{\nu }^{(\text{II})}$ (red) for the phenoxyl/phenol system. Since this reaction is electronically nonadiabatic, the vibronic coupling is the product of the electronic coupling V^el and the overlap of the reactant and product proton vibrational wavefunctions $S_{\mu \nu }\equiv \langle {\varphi }_{\mu }^{(\text{I})}\mid {\varphi }_{\nu }^{(\text{II})}\rangle$. (b) Electronically adiabatic ground state potential energy curve and the corresponding proton vibrational wavefunctions for the benzyl/toluene system. Since this reaction is electronically adiabatic, the vibronic coupling is equal to half of the energy splitting Δ between the symmetric (cyan) and antisymmetric (magenta) proton vibrational states for the electronic ground state potential energy surface. For illustrative purposes, the excited vibrational state is shifted up in energy by 0.8 kcal/mol. Figure reproduced with permission from Ref. [31].