CHARGE-TRANSFER-INDUCED FRENKEL EXCITON SPLITTING IN CRYSTALLINE FULLERENE

Temperature-dependent second-harmonic-generation (SHG) studies of exci tons in crystalline fullerene are examined using theoretical estimates of the electrostatic energies of charge-transfer (CT) states. The obs erved Frenkel exciton splittings are interpreted in terms of indirect interactions mediated by the CT manifold. Model calculations reproduce the change in width of the SHG spectrum with temperature and rational ize its shape.