MOLECULAR FIRST HYPERPOLARIZABILITY OF PUSH-PULL POLYENES - RELATIONSHIP BETWEEN ELECTRONIC AND VIBRATIONAL CONTRIBUTION BY A 2-STATE MODEL- REPLY

In this paper we justify the approximations we have used in the treatm ent of Raman intensities in the paper being commented on [C. Castiglio ni, M. Del Zoppo, and G. Zerbi, Phys. Rev. B 53, 13 319 (1996)]. This discussion gives further support to the applicability of the expressio ns presented by Castiglioni, Del Zoppo, and Zerbi [Phys. Rev. B 53, 13 319 (1996)], which relate electronic and vibrational first hyperpolar izability of push-pull polyenes.