Formaldehyde, 17O isotopolog
Species tag 031514
Date of EntryFeb. 2017
ContributorH. S. P. Müller

The experimental data were summarized by
(1) H. S. P. Müller and F. Lewen, 2017, J. Mol. Spectrosc. 331, 28.
Besides new submillimeter data up to 1.5 THz from that study, transition frequencies were taken from
(2) W. H. Flygare and J. T. Lowe, 1965, J. Chem. Phys. 43, 3645;
and from
(3) R. Cornet, B. M. Landsberg, and G. Winnewisser, 1980, J. Mol. Spectrosc. 82, 253.
The predictions should be accurate enough for all astronomical observations. Predictions with calculated uncertainties exceeding 0.2 MHz should be viewed with caution.
The 1H hyperfine splitting has not been resolved in the laboratory and is unlikely to matter in astronomical observations. 17O hyperfine splitting is important at long wavelength, but probably negligible in the submillimeter. A separate hyperfine calculation is provided up to 600 GHz. The partition function takes into account the hyperfine splitting.
At low temperatures, it may be necessary to discern between ortho-H2C17O and para-H2C17O. The ortho states are described by Ka odd, the para states by Ka even. The nuclear spin-weights are 3 and 1 for ortho-H2C17O and para-H2C17O, respectively. The JKaKc = 111 is the lowest ortho state. It is 10.5126 cm–1 above ground.
The dipole moment was assumed to agree with that of the main isotopolog, see e030501.cat.

Lines Listed1544
Frequency / GHz< 3600
Max. J51
log STR0-8.3
log STR1-7.0
Isotope Corr.-3.426
Egy / cm–10.0
 µa / D2.3317
 µb / D 
 µc / D 
 A / MHz281965.8
 B / MHz37810.313
 C / MHz33216.494
detected in ISM/CSMyes

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