Ab initio study of the electronic spectrum of HOBr

The structure and vibrational spectra of HOBr calculated using ab initio post-Hartree-Fock methods are in reasonable agreement with experiment. Vertical excitation energies and oscillator strengths have been computed for transitions to low-lying excited states of HOBr. The peaks at 350 and 280 nm in the gas-phase absorption spectrum reported by Orlando and Burkholder (J. Phys. Chem. 1995, 99, 1143-1150) may be attributed to the à ¹A′ and B̃ ¹A′ states, respectively. The calculations predict another absorption with a maximum at about 477 nm due to the ã ³A″ state.