INTERPRETATION OF THE VIBRATIONAL STRUCTURE OF THE EMISSION AND ABSORPTION-SPECTRA OF C-60

The vibronic intensity borrowing activity of the lowest electronically excited singlet states of C60 has been obtained through quantum chemical calculations. The vibrational structure of the UV-visible spec ra is found to be dominated by false origins. The calculated intensities of the false origins of the T1g state agree with the vibrational structure observed in the fluorescence spectrum. The same false origins are recognized to be responsible for the vibrational structure of the red edge portion of the absorption spectrum. Only two bands in the spectra are assigned as combination bands involving an a(g) or a Jahn-Teller active mode. Absorption bands that may be associated with false origins of the states T2g and G(g) which are quasidegenerate with S1 are tentatively assigned.