Description

Transition frequencies were taken from
(1) A. H. Saleck, M. Tanimoto, S. P. Belov, T. Klaus, and G. Winnewisser, 1995, J. Mol. Spectrosc. 171, 481.
Also included in the fit are far-infrared transitions from
(2) J.-M. Flaud, C. Camy-Peyret, and J. W. C. Johns, 1983, Can. J. Phys. 61, 1462.
The uncertainties of (1) seemed to be too large; they have been set to 50 and 100kHz for the most part. The data from (2) were not quite reproduced within experimental uncertainties. Since the rms error was with about 1.2 only slightly larger than 1.0 and since there were no transitions whose residuals exceeded three times the uncertainties no adjustments of the uncertainties were made. Some higher order parameters were taken from H2S.
33S hyperfine splitting was retained throughout the predictions because it is important for the low energy transitions and can not be neglected for many higher energy transitions.
The predictions should be reliable as long as the uncertainties do not exceed 5MHz.
At low temperatures, it may be necessary to discern between ortho-H233S and para-H233S. The ortho and para states are described by Ka+Kc being odd and even, respectively. The nuclear spin-weights are 3 and 1 for ortho-H233S and para-H233S, respectively. The JKaKc= 101 is the lowest ortho state. It is 13.742cm–1 above ground. Aug. 2011: separate para and ortho predictions are available along with separate para and ortho partition function values. Note: the spin-weight of 3 for the separate ortho predictions has been eliminated.
The dipole moment was assumed to agree with that of H2S, see e034502.cat.