Total Absorption Cross Section for UV Excitation of Sulfur Monoxide.

In a new study on sulfur monoxide, new ab initio potential energy curves are developed for excited states AΠ, BΣ, CΠ, and C'Π and for three states that are unassigned in the literature, which we numerically name 3Σ, 4Π, and 5Π. All these excited states have allowed transitions from ground state, XΣ. The ab initio calculations were performed using the MRCI-F12+Q/aug-cc-pV(5+d)Z level of theory implemented in MOLPRO2015. On the basis of close-coupling R-matrix theory, fine structure absorption cross sections of isotopically substituted sulfur monoxide are calculated for wavelengths of 190-300 nm. The spectra are shown at the highest possible resolution (FWHH ≈ 0.15-0.18 cm) for reference and future studies. The effects of self-shielding and possible mutual shielding are discussed.