LOCAL DENSITY FUNCTIONAL CALCULATIONS OF THE POLARIZABILITY AND 2ND-ORDER HYPERPOLARIZABILITY OF C-60

Local density functional (LDF) calculations of the values of alpha and gamma for benzene and C60 (I(h)) have been made with a double numerical basis set augmented with polarization functions. The geometries were optimized resulting in r(C-C) = 1.389 angstrom for benzene and r(C-C) = 1.442 angstrom and r(C=C) = 1.386 angstrom for C60. The dependence of alpha and gamma for benzene on the computational parameters of the mesh quality, field strength, and AH convergence was studied. Values of alpha = 1.012 x 10(-23) cm3 and gamma = 6.24 x 10(-36) esu were calculated for benzene. For C60, values of alpha = 7.79 x 10(-23) cm3 and gamma = 15.9 x 10(-36) esu were calculated. The value of gamma for C60 is the same magnitude as aa previously calculated semiempirical result and is much lower than the observed values. Possible reasons for the discrepancy between the calculated and experimental values are discussed.