The onsite molecular Coulomb interaction (U) of solid C60 is determine
d by means of a comparison of the selfconvolution and the KVV Auger sp
ectrum and found to be 1.6 +/- 0.2 eV and nearly independent of the mo
lecular orbitals. This value of U leads to Frenkel type molecular exci
tons in the 1.5 - 2 eV range.