OPTICAL PROPERTIES OF QUASI-ONE-DIMENSIONAL MOLECULAR CRYSTALS WITH DIFFERENT POLARIZATIONS.

Quasi-one-dimensional organic compounds in which the acceptor TCNQ molecules form dimers are studied. Site orbitals describing the pi electron in half of the TCNQ molecule are introduced. Hubbard's model is generalized so as to take into account the Coulomb repulsion between two electrons at one site. It is shown that the optical excitations of the electron are associated with intramolecular vibrations both when the incident light is polarized along the TCNQ chains and when the incident radiation is polarized transverse to the chains. The conductivity of the system with different polarizations is calculated taking into account the electrovibrational interaction.