Vibronic spectra of charge transfer excitons and of mixed charge transfer and Frenkel excitons

The vibronic spectra of charge transfer excitons have been studied in the two cases of vibronics of pure charge transfer excitons and of strongly mixed Frenkel and charge transfer excitons. Only the linear exciton–phonon coupling is taken into account. The spectra of linear absorption are calculated for the exciton parameters of a PTCDA crystal.