Theoretical estimation of nonlinear optical properties of Langmuir-Blodgett films

The quadratic hyperpolarizability of molecules of the push-pull type enteri ng some Lengmuir-Blodgett films with the expressed nonlinear optical proper ties are calculated in the framework of the time-dependent Hartree-Fock sem iempirical approximation. The list of molecules includes neutral as well as charged chromophores. The Madelung interaction in a film is taken into acc ount exactly in both cases that allows comparing the hyperpolarizability of these types of compounds. (C) 2001 Elsevier Science B.V. All rights reserv ed.