For each C05-C22 diabatic state, its energy's pattern of variation in the conformational space resembles that of C22-PC113. Consistent with our observation for C22-PC113, the E =1 of the C05-C22 dimer never exceeds the lower |C05 * C22 * ⟩ state of the two LE states, resulting in a redshift compared with the lower energy monomer. Here, the variation of the dimer E =1 in the conformation space also shows a complex pattern due to the distribution of ΔE =& , whereas the impact of ΔE +;<9 and ΔE >+? is negligible due to their smaller amplitude. The local minima of E =1 usually located around the center of carbon-carbon bonds, corresponding to the parallel-displaced configurations [Figure (a)-(c)]. This behavior is different from the C22-PC113 dimer as the eclipsed conformation fails to maximize the orbital overlap between the frontier orbitals of C05 and C22 when aligning their TDMs. After rotating C22 by 60°, the eclipsed conformation coincides with the local minimum of E 5% (Figure ). The magnitude of the ΔE %A!B is even larger than that of the C22-PC113 dimer (note the factor of ΔE %A!B and color scaling of Figure ) as the pi-pi interaction area of C05 is larger than PC113, meaning that the most stable geometry of C05-C22 exciplex may close to that of its ground state. In summary, the structural difference between C05 and PC113 affects the variation pattern of the energy terms in the conformational space, but the dimer fluorescence is always lower than the lowest monomer fluorescence energy, with the main contribution still from superexchange.