CALCULATIONS ON THE SPECTRA AND NONLINEAR 3RD-ORDER OPTICAL SUSCEPTIBILITY OF C70

The equilibrium geometry and UV-visible spectra of C70 were examined using semiempirical INDO/2 and INDO/CI methods. The results obtained are in good accord with experimental results. On the basis of correct electronic spectra, calculations of the nonlinear third-order optical susceptibility (gamma(ijkl)) of C70 were performed using the INDO/SDCI method combined with a sum-over-states expression. The calculated value for [gamma] (-2omega; omega, omega, 0) is 0.882 X 10(-33) esu (omega = 1.91 mum), which is in good agreement with observation. (c) 1994 John Wiley & Sons, Inc.