SIMULATION OF PHTHALOCYANINE DIMER SPECTRA BY EXTENDED DIPOLE MODEL

Optical absorption spectra of phthalocyanine (Pc) dimers are simulated for a series of assembling structures in which two Pc molecules are p arallel to each other. Intermolecular interaction that induces change of spectra is calculated by extended dipole model and extended double- dipole model. The splitting feature of the dimer spectra shows several spectral patterns, depending on a structural parameter, namely, the s lipping distance, Among the patterns we find spectral characteristics of major crystals such as alpha-form and beta-form by choosing the app ropriate parameter values. By using dipole lengths of realistic molecu lar dimension, simulated interaction energy approaches the experimenta l scale for a coaxial face-to-face structure.