STATIC 3RD-ORDER POLARIZABILITY CALCULATIONS FOR C-60, C-70, AND C-84

Valence electron contributions to the static molecular third-order pol arizabilities (gamma) are calculated for C-60, C-70, and two stable st ructures of C-84 (D-2 and D-2d). The method utilized is based on the f inite-field approach coupled with semiempirical polarization calculati ons on all-valence electrons. An increase in the third-order polarizab ility contributions is observed for molecular structures with a reduct ion in group symmetry, in agreement with recent experimental observati ons for these fullerenes. This increase is attributed mainly to the ap pearance of aromatic structures within the molecules as well as to the increase in molecular volume.