Theoretical search for molecular aggregates with strong non-linear optical activity

Electronic correlation and electron-molecular vibration (EMV) coupling are effects of the same order of magnitude in molecular donor-acceptor complexes. A model is considered where both effects are taken into account explicitly. Calculations of static first and second hyperpolarizabilities are reported for a planar aggregate of five sites with two electrons which models molecules with two pairs of different side groups attached to the central part. These results may be used for future synthesis of molecules with required optical properties. (C) 2001 Elsevier Science B.V. All rights reserved.