The UV spectrum of linear C 6 has been observed, and correlates well with previous theoretical results. However, for the D 3 h structure of C 6 , predicted to be more stable, no UV spectrum is available. Using a 9s5p1d/5s3p1d basis set, vertical excitation energies and oscillator strengths of both singlet and triplet states, for D 3 h and D 6 h structures of C 6 , were calculated by MR-CI methods. For the D 3 h singlets, with an X 1 A 1 ' ground state, intense transitions are predicted to 1 1 E ' at 2.96 eV, and to 5 1 E ' at 6.9 eV. For the D 6 h singlets, with an X 1 A 1 g ground state, the most intense transition is predicted for 1 1 E 1 u at 4.8 eV. Comparison with the π-π* spectrum of benzene has been made. The lowest triplet states lie 2.16 eV above X 1 A ' 1 for D 3 h , and 1.90 eV above X 1 A 1 g for D 6 h symmetry.