Chiral superamolecular complexes, formed from the chiral assembly of molecular components or achiral building blocks, are prominent in supramolecular chemistry and materials science due to their intriguing properties. Their photophysical properties are determined not only by the specific chemical structure of the sole organic molecules, but also by their organization which spans various hierarchical levels from first-order superamolecular arrangements to nano/mesoscale structures in solution or solid state. Among various π-conjugated molecules, perylene diimides(PDIs) have become appealing for various technological applications, including electronic displays and solar cells, due to their unique and tunable optoelectronic properties and low production costs. PDIs offer another advantage of easily controllable morphology. Over the past decades, noncovalent interactions like hydrogen bonding, metal-ion coordination, electrostatic interactions, π -π stacking, dipole-dipole interactions and hydrophobic interactions have been identified as key in constructing diverse superstructures from engineered smallmolecule building blocks. Their rigid core forms strong π-π-stacking interactions, adjustable via substituent at the imide, bay, ortho positions, allowing the formation of various helical or creeper aggregates. Recently, Shang et.al. synthesized two different bay-substituted PDIs: (R)-CN-CPDI-Ph (PDI-CN) and (R)-2F-CPDI-Ph (PDI-F), which self-assemble into well-defined one-dimensional nanomaterials in various solvents, and found that the desired morphologies with bay-substituted PDIs can be achieved by precise molecular design and suitable solvents. In analyzing the aggregated states of chiral π-conjugated systems, electronic circular dichroism(ECD) spectroscopy plays a crucial role, because ECD is strictly allied to supermolecular chirality and is sensitive to their absolute configuration as well as to its features of conformation. Molecular ECD spectra can be experimentally measured and theoretically calculated. However, for large aggregates, using precise quantum mechanics (QM) methods to simulate ECD is computationally expensive, as these systems typically consist of hundreds to thousands of atoms and an even greater number of vibrational degrees of freedom. Usually, the Frenkel exciton model is adopted to describe the photo-induced processes of weakly-coupled multichromophoric systems. The well-established ECD exciton chirality rule was thus derived to interpret the ECD spectra without the requirement of QM calculations. The ECR correlates the sign of an exciton couplet (two ECD bands with opposite sign and similar intensity) with the overall molecular stereochemistry, including the absolute configuration. The ECR applies the concepts of exciton coupling, and assumes that the coupling is dominated by the Coulomb coupling and the exciton coupling mechanism is the major source of the observed ECD signals. However, for the multichromophores that are closely stacked or bond-linked, interactions between chromophores can cause significant overlap of wavefunction on neighboring chromophores. That can result in through-space or bond-mediated charge delocalization along the stacking or bonding direction. As a result, photo-induced interchromophore electronic exchange or charge-transfer excitations (CTEs) occur readily, with the electron and hole residing on adjacent chromophores. Many previous studies have reported that the CTEs can significantly affect both the spectral lineshapes and exciton dynamics of the closely packed molecular aggregates. Indeed, unlike inorganic crystalline, π-conjugated molecular aggregates exhibit optical excitations and charge transport that require substantial nuclear rearrangements, leading to strong vibronic coupling between electronic excitations and molecular vibrations. The vibronic effect on the absorption spectra of aggregates have been widely discussed, but studies on the vibrationally-resolved ECD spectra of aggregates are scarce, and most works are limited to the electronic state level and molecular calculations on individual chromophoric systems. The vibronic effect on ECD spectra of aggregates based on the vibronic exciton theory have been reported but these works neglected the influence of CTEs to ECD spectra (e.g. Refs. 61-63).