Figure 5.

Dependence of the constant interstate coupling E_ij(0) (for i ≠ j) and the LE–CT energy gap (ΔE_CT–LE(0)) with different parameters of the PDI dimer: (a) R_π, (b) R_s, (c) R_∥, (d) α, (e) β (component along R_s), and (f) β (component along R_∥). The scans were performed on the structure with R_π = 4.0 Å, changing one parameter at time and setting all others to zero. Because several choices of E_LE–CT(0) are possible, we specify that only the E_LE–CT coupling between the states |L₁⟩ and |CT(1 → 2⟩ is reported because it is larger in magnitude. By symmetry, the |L₂⟩ and |CT(2 → 1⟩ coupling is the same.