Theoretical studies of absorption spectra of SO2 isotopomers

We investigate the isotopic variation of the C ∼ -state absorption spectrum of sulfur dioxide (SO2). Low-lying vibrational energy levels of four isotopomers were obtained using the Lanczos method on a recent ab initio potential energy surface of the C ∼ -state of SO2. The corresponding absorption spectra up to 185 nm were determined using a Chebyshev method with ab initio transition dipole functions. Implications for the recently observed mass-independent isotope effects are discussed.