The data have been taken from
(1) H. Møllendal, L. Margulès, A. Belloche, R. A. Motiyenko, A. Konovalov, K. M. Menten, and J. C. Guillemin, 2012, Astron. Astrophys., 538, Art. No. A51.
Predictions with uncertainties larger than 0.5 MHz should be viewed with caution. Transititions with such large uncertainties are probably too weak to be observable by radio-astronomical measn.
Low-lying vibrational states contribute substantially to the partition function above about 75 K. Estimates of vibrational contributions have been given in (1).
The ab initio dipole moment components were determined in (1).