Ab initio variational calculation of dynamic polarizabilities and hyperpolarizabilities I. Polarizability and quadratic hyperpolarizability of water, carbon monoxide and hydrogen fluoride

We present the variation-perturbation method for the ab initio calculation of dynamic polarizabilities and quadratic hyperpolarizabilities. After a summary of the general theory, we report test calculations on the water, carbon monoxide and hydrogen fluoride molecules. Excellent agreement with both experimental and accurate ab initio values is reached when an SCF/LCAO/MO calculation in a 6-311 + + Gu** basis set is made for generating the singly-excited Slater determinants over which the first-order correction to the wave function is expanded. Dispersion curves are also reported, a distinctive feature of this technique as compared to many computational schemes currently in use. (C) 1998 Elsevier Science B.V. All rights reserved.