CHARGE-TRANSFER EXCITON BAND-STRUCTURE IN THE FULLERENE CRYSTAL-MODELCALCULATIONS

A three-dimensional analog of the Merrifield model of the coupling bet ween Frenkel and charge-transfer (CT) excitons of the C-60 fullerene c rystal is presented. The model is based on the nearest-neighbor approx imation for the off-diagonal interactions and is essentially nonempiri cal. The parameters are:estimated from free-molecule data and from the results of theoretical calculations published by other authors. The b and structure of CT excitons in C-60 is calculated and discussed in th e context of available experimental evidence. Residual ambiguities in the parametrization are removed by calculation of the electroabsorptio n spectrum and comparison with experiment, as described in the accompa nying paper. (C) 1998 American Institute of Physics. [S0021-9606(98)71 042-6]