Formaldehyde, doubly deuterated isotopologue with 18O
Species tag 034505
Date of EntryJan. 2016
ContributorH. S. P. Müller

Transition frequencies with microwave accuracy were determined by
(1) D. Dangoisse, E. Willemot, and J. Bellet, 1978, J. Mol. Spectrosc. 71, 414;
and 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 the D2CO parameters.
The uncertainties of (2) appeared to be quite conservative. Therefore, we decreased these uncertainties by a factor of 1.5. The data from (1) have not been merged.
The predictions of very high lying rotational states have been improved with respect to the first entry. The predictions should be adequate throughout not only for astronomical observations but also for laboratory spectroscopy.
At low temperatures, it may be necessary to discern between ortho-D2CO and para-D2CO. The ortho states are described by Ka even, the para states by Ka odd. The nuclear spin-weight ratio is 2 : 1 for ortho-D213CO : para-D213CO. The JKaKc = 111 is the lowest para state. It is 5.5608 cm–1 above ground.
The dipole moment was assumed to agree with that of D2CO, see e032502.cat.

Lines Listed1438
Frequency / GHz< 2000
Max. J62
log STR0-7.0
log STR1-6.0
Isotope Corr.-10.319
Egy / cm–10.0
 µa / D2.347
 µb / D 
 µc / D 
 A / MHz141649.3
 B / MHz30594.80
 C / MHz25064.16
detected in ISM/CSMno

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