Very accurate millimeter and submillimeter transition frequencies were added with respect to the first entry from May. 2004. These were taken from
(1) H. S. P. Müller, A. Maeda, S. Thorwirth, F. Lewen, S. Schlemmer, I. R. Medvedev, M. Winnewisser, F. C. De Lucia, and E. Herbst, 2019, Astron. Astrophys. 621, Art. No. A143.
The first entry was limited to transition frequencies which were reported by
(2) H. Minowa, M. Satake, T. Hirota, S. Yamamoto, M. Ohishi, and N. Kaifu, 1997, Astrophys. J. 491, L63.
Because of the lower symmetry of HDCS with respect to the main isotopomer, spin-statistics do not have to be considered !
This entry is sufficiently accurate for all astronomical purposes. Transition frequencies with calculated uncertainties exceeding 0.2 MHz should be viewed with caution.
The dipole moment was derived from those of the main and doubly deuterated isotopologs, see e046509.cat and e0048507.cat. There is a small b-dipole moment component of about 0.08 D. However, since no b-type transitions have been observed, no reliable predictions can be made for this type of transitions.