Figure 3.

(A) A slice of the potential energy surface along the diagonal of the normal mode coordinate, Q, as each substituted pentacene monomer in the dimer relaxes along the 1435 cm^–1 mode. The values at each point are calculated at the 8o8e level of theory (see the Supporting Information for details). The ME state is higher than the LE states at Q = (0,0), and the avoided crossing is Q = (0.33,0.33). (B) Percent diabatic state composition of the three lowest excited adiabatic states of BP-37 as a function of Q demonstrating strong mixing at Q = (0.33,0.33) and the change in character of adiabatic states S₁ and S₃ as we move from Q = (0,0) to Q = (1.3,1.3). (C) Representation of the 1435 cm^–1 mode in pentacene and the postulated structure of T₁ in a pentacene monomer, achieved through the avoided crossing.