Lastly, the Frenkel exciton Hamiltonian was constructed by considering the solvent molecules from the large QM region. These results were compared to the result of the full QM cluster calculations. In general the exciton model reproduced the reference spectra for all three solvents with an accuracy comparable to be between the small and large QM calculations. This was observed as minor peak shifts in both the chloroform and the dimethyl sulfoxide (for the anionic chromophore) spectra, which most likely is due to over polarization effects.