where E C is the excitation energy of the circular chromophore, and E a L and E b L are the excitation energies of the two linear chromophores (labeled a and b). In this system, the linear-circular coupling, V LC , carries a complex phase e.g., as in Eq. 9, while the linear-linear interaction V LL does not. Specifically, V a LC = cos θ a V x ± sin θ a V y , with a similar expression for V b LC .