Figure 6.

Ground (blue) and excited-state (maroon) energies (eV) for the singlet exciplex of tetracyanoethylene (TCNE) and naphthalene in multistate energy decomposition analysis. The S₀ complex geometry is used. The energies are given relative to that of adiabatic ground state of isolated monomers in equilibrium geometry. Three charge transfer states (in brown) appear at the superexchange stage of MS-EDA. The effective adiabatic excitation energies of the separate monomers in the exciplex geometries are 4.62, 4.61, and 4.65 eV for the first, second, and third exciton states, originating dominantly from the π → π* state of TCNE, and the L_b and L_a states of naphthalene. Energies corresponds to excitation and resonance terms defined in Scheme 2.