Cohesion and optical activity of organic chain compounds

Unusual cohesion (fractional charge transfer, charged sheets) and optical activity (far infrared anomalies) of organic chain compounds are explained within the theory which includes interband processes, i.e. dipole-dipole and monopole-dipole interactions, on both, donor and acceptor, chains. The analysis based on our recent tight-binding dielectric formalism, shows that these unusual properties are related to the softening of hybridized collective modes.