EN
A cluster approach is used for a theoretical description of the optical properties of pentamerized low-dimensional molecular crystals. Electronic correlations are taken into account explicitly in the Hubbard model for 1, 2, 3, 4 and 5 electrons in a linear pentamer, as well as coupling of electrons to the totally symmetric intramolecular vibrations. Calculated absorbance is compared to the measured one in pentamerized salt of TCNQ and TTF molecules.