CNDO/S-CI Calculations of Non-linear Optical Porperties of Organic Molecules

In this paper a program for computing the first hyperpolari zabilities of organic molecules has been compiled using quantum chemical semiempirical CNDO/S-CI method and perturbation theory. The convergence of the calculations with respect to the number of configurations is investigated. Test calculations on a series of conjugated organic molecules are in good agreement with experimental data. The effect of the molecular structure such as the subsititution partten on the benzene ring and the length of conjugated carbon chain upon the molcular first hyperpolarizability has also been discussed.