The Electronic Spectrum of C60

Abstract Using the CASSCF/CASPT2 methodology the electronic transitions HOMO → LUMO, HOMO → LUMO+1, HOMO-1 → LUMO and HOMO-2 → LUMO are determined for C60. Comparison to experiment suggests an accuracy better than 0.3 eV. Some illustrative examples are (with experimental data within parentheses) the first excited state, 3 T 2 g , at 1.54 eV (1.60 eV), the two lowest-lying 1 T 1 u states (for spin- and symmetry-allowed transitions) at 3.09 eV (3.08 eV) and 3.19 eV (3.30 eV) and the lowest singlet excited states ( 1 G g , 1 T 1 g , 1 T 2 g , 1 H g ) at [1.84, 1.95] eV (1.90 eV with mainly 1 G g and 1 T 1 g and minor 1 T 2 g character).