The experimental data were taken from
(1) V. D. Gordon, M. C. McCarthy, A. J. Apponi, and P. Thaddeus, 2001, Astrophys. J. Suppl. Ser. 134, 311.
The reported uncertainties are very conservative and have been adjusted. Predictions beyond 60 GHz should be viewed with caution.
The dipole moment was estimated by
(2) H. S. P. Müller, 2018, unpublished.