When the LE and CTE states are decoupled, the resulting absorption spectra predominantly display two peaks while the ECD spectra reveal the sign of an exciton couplet (two ECD bands with opposite sign and similar intensity). This observation aligns with the conventional exciton chirality rule. The slight difference in the intensities of the positive and negative peaks can be attributed to the slight differences in the excitation energies and dipole strengths of the fragments within the oligomer we considered in actual numerical calculations. The conventional ECR assumes that each fragment is identical and has uniform dipole strength.