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The low-energy wing of the C^~1B₂ ← X^~1A₁ absorption spectra for SO₂ in the ultraviolet region is computed for the 32S,³³S,³⁴S and ³⁶S isotopes, using the recently developed ab initio potential energy surfaces (PESs) of the two electronic states and the corresponding transition dipole surface. The state-resolved absorption spectra from various ro-vibrational states of SO₂(X^~1A₁) are computed. When contributions of these excited ro-vibrational states are included, the thermally averaged spectra are broadened but maintain their key characters. Excellent agreement with experimental absorption spectra is found, validating the accuracy of the PESs. Here, the isotope shifts of the absorption peaks aremore » found to increase linearly with energy, in good agreement with experiment« less

Transport properties for collisions of oxygen atoms with hydrogen atoms and hydrogen molecules have been computed by means of time-independent quantum scattering calculations. For the O(³P)–H(²S) interaction, potential energy curves for the four OH electronic states emanating from this asymptote were computed by the internally-contracted multi-reference configuration interaction method, and the R-dependent spin-orbit matrix elements were taken from Parlant and Yarkony [J. Chem. Phys. 110, 363 (1999)]. For the O(³P)–H₂ interaction, diabatic potential energy surfaces were derived from internally contracted multi-reference configuration interaction calculations. Transport properties were computed for these two collision pairs and compared with those obtained with themore » conventional approach that employs isotropic Lennard-Jones (12-6) potentials.« less