Hyperpolarizabilities of substituted conjugated molecules. I. Perturbated INDO approach to monosubstituted benzene

Abstract

Following experimental studies on benzene substitutes, we have attempted to derive some results on their molecular hyperpolarizabilities from a semiempirical treatment of the Hartree–Fock equations extended to all valence electrons (INDO procedure). The INDO equations are modified so as to introduce a dipolar perturbation, for molecules including atoms of the third line of the Mendeleeiev classification. Hyperpolarizabilities, defined as field derivatives of the dipole moment are given finite difference expressions. Results for benzene and a number of benzene monosubstitutes are discussed.