The transition frequencies were taken from
(1) S. Spezzano, F. Tamassia, S. Thorwirth, P. Thaddeus, C. A. Gottlieb, and M. C. McCarthy, 2012, Astrophys. J. Suppl. Ser. 200, Art. No. 1.
The data set is very small, therefore, predictions have been truncated at J = 6. Predictions may be good up to J = 3 and for K_c = J or J – 1.
The hyperfine splitting of ¹³C and D nuclei has been resolved to a large degree in (1). The hyperfine splitting may be be resolvable in astronomical observations of cold sources. Therefore, a separate hyperfine calculation is provided up to J = 3 and up to 150 GHz. The partition function values include the spin-multiplicity of the D nucleus.
Note: Non-trivial spin-statistics do not matter for this low symmetry (C_S) isotopolog.
The total dipole moment was taken from the main species, see e038506.cat. The large rotation of the inertial axis induces a sizable a-dipole moment component. The relative magnitude was derived in (1).