Vinyl mercaptan occurs in two conformers, the lower energy syn conformer and the anti conformer, which is about 60 K (or 42 cm^–1) higher in energy. The experimental transition frequencies were taken from
(1) M.-A. Martin-Drumel, K. L. K. Lee, A. Belloche, O. Zingsheim, S. Thorwirth, H. S. P. Müller, F. Lewen, R. T. Garrod, K. M. Menten, M. C. McCarthy, and S. Schlemmer, 2019 Astron. Astrophys. 623, Art. No. A167.
The energy difference was calculated in (1).
Predicted transition frequencies should be sufficient for all observational purposes, but should be viewed with caution if the uncertainties exceed 0.2 MHz.
The partition functions takes into consideration only the ground vibrational states of both conformers. Individual contributions are available. Vibrational correction factors should be available in the future.
The dipole moment components were reported in
(2) M. Tanimoto, V. Almond, S. W. Charles, J. N. Macdonald, and N. L. Owen, 1979 J. Mol. Spectrosc. 78, 95.