Rotational transition frequencies from a laboratory study and from astronomical observations were reported by
(1) J. Cernicharo, C. Cabezas, Y. Endo, N. Marcelino, M. Agúndez, B. Tercero, J. D. Gallego, and P. de Vicente, 2021, Astron. Astrophys. 646, Art. No. L3.
Calculations beyond 120 GHz should be viewed with caution. The dipole moment was taken from a quantum chemical calculation by
(2) S. Thorwirth, M. E. Harding, O. Asvany, S. Brünken, P. Jusko, K. L. K. Lee, T. Salomon, M. C. McCarthy, and S. Schlemmer, 2020 Mol. Phys. 118, Art. No. e1776409.