The initial experimental frequencies have been reported by
(1) D. Dangoisse, E. Willemot, and J. Bellet, 1978, J. Mol. Spectrosc. 71, 414.
The very sparse data set of the first entry from Sep. 2008 was supplemented recently by an extensive set of lines recorded betwenn 1.1 and 1.52 THz and reported by
(2) O. Zakharenko, R. A. Motiyenko, L. Margulès, and T. R. Huet, 2015, J. Mol. Spectrosc. 317, 41.
Some higher order parameters were estimated from HDCO parameters from that work.
The transitions from (1) were not merged. The predictions should be sufficiently accurate for all astronomical purposes. Predictions with uncertainties larger than 0.3 MHz should be viewed with caution.
Because of the lower symmetry of HD¹³CO with respect to the main isotopic species, spin-statistics do not have to be considered !
The dipole moment was assumed to agree with that of HDCO, see e031501.cat.