Cyclopropenylidene, doubly deuterated isotopolog
Species tag 040514
Date of EntryJuly 2012
ContributorH. S. P. Müller

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.
Predictions with uncertainties larger than 0.3 MHz should be viewed with caution because of the limited experimental data. Nevertheless, the data set may well be sufficient for astronomical observations.
The hyperfine splitting of the two equivalent 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 = 4 and up to 120 GHz. The partition function values include the spin-multiplicity of the two D nuclei.
At lower temperatures, it may be useful to distinguish between ortho-c-C3D2 and para-c-C3D2. The ortho and para levels are described by Ka + Kc = even and odd, respectively, with a spin-weight ratio of 2 : 1. The JKaKc = 101 level is the lowest para state. However, it is only 1.267823 cm–1 above ground. Any pronounced effect will likely be restricted to absorption lines originating in 101.
The dipole moment was assumed to agree with that of the main species, see e038508.cat.

Lines Listed1869
Frequency / GHz< 1000
Max. J38
log STR0-6.0
log STR1-4.0
Isotope Corr.-7.64
Egy / (cm–1)0.0
 µa / D 
 µb / D3.27
 µc / D 
 A / MHz31649.10
 B / MHz24298.62
 C / MHz13709.85
detected in ISM/CSMyes

Database maintained by Holger S. P. Müller and Sven Thorwirth, programming by D. Roth and F. Schloeder