Rovibrational bound states of SO2 isotopologues. II: Total angular momentum J = 11–20

Abstract

In a two-part series, the rovibrational bound states of SO2 are investigated in comprehensive detail, for all four stable sulfur isotopes 32–34,36S. All low-lying rovibrational energy levels—both permutation-symmetry-allowed and not allowed—are computed, for all values of total angular momentum in the range J=0–20. The calculations have carried out using the ScalIT suite of parallel codes. The present study (Paper II) examines the J=11–20 rovibrational levels, providing symmetry and rovibrational labels for every computed state, relying on a new lambda-doublet splitting technique to make completely unambiguous assignments. Isotope shifts are analyzed, as is the validity of “J-shifting” as a predictor of rotational fine structure. Among other ramifications, this work will facilitate understanding of mass-independent fractionation of sulfur isotopes (S-MIF) observed in the Archean rock record—particularly as this may have arisen from self shielding. S-MIF, in turn is highly relevant in the broader context of understanding the “oxygen revolution”.