For the lowest few singlet excited states (including the S 1 bright state), PR e-h ranges from 3.8-6.7 with PR e-h > 5 in all but one case, indicating nearly complete delocalization. The S 1 , S 2 , and S 3 states are characterized by zero, one, and two nodes along this coordinate, respectively, and could be interpreted as sequential states belonging to a single exciton band, with particle-in-a-box character along the center-ofmass coordinate. The S 4 , S 5 , and S 6 states (again with zero, one, and two nodes, respectively) constitute a second exciton band. This is consistent with the idea that the intracule and extracule coordinates r elec ±r hole sometimes behave as separable quasiparticle coordinates in conjugated polymers. However, Plasser and Lischka 186 question whether these should indeed be characterized as FE states, given the fairly significant coherence lengths (e.g., L coh = 3.9 for S 1 and L coh = 5.0 for S 4 ). These values quantify the anti-diagonal length in the Ω heat maps and can be interpreted as electron-hole separation, measured in units of PV monomers, and the computed values suggest that the electron and hole are well separated, unlike the conventional FE picture of a tightly-bound electron and hole.