The first entry of Nov. 2001 was reevaluated and extended. As earlier, accurate MW laboratory data are from
(1) Y. Hirahara, Y. Oshima, and Y. Endo, 1993, Astrophys. J. 408, L113; and from
(2) V. D. Gordon, M. C. Mc Carthy, A. J. Apponi, and P. Thaddeus, 2001, Astrophys. J. Suppl. Ser. 134, 311.
Included are also several lower mmW transition frequencies from astronomical observations by
(3) R. Fuentetaja, C. Cabezas, Y. Endo, M. Agúndez, A. Godard Palluet, F. Lique, B. Tercero, N. Marcelino, P. de Vicente, and J. Cernicharo, 2025, Astron. Astrophys. 702, Art. No. A23.
Transition frequencies with calculated uncertainties exceeding 0.1 MHz should be viewed with caution.
The dipole moment is from a quatum-chemical calculation from
(4) H. S. P. Müller, 2018, unpublished.
The value should be better than the one applied previously, but should be still viewed with slight caution.