The largely millimeter wave transition frequencies were taken from
(1) C. Cabezas, K. Vávra, G. Molpeceres, L. Kolesniková, M. Agúndez, G. Vylitová, N. Marcelino, L. Hrubčík, R. Fuentetaja, T. Uhlíková, B. Tercero, J. Koucký, G. Esplugues, P. Kania, P. de Vicente, Š. Urban, and J. Cernicharo, 2025, Astron. Astrophys. 698, Art. No. L24.
Additional, largely microwave frequencies are from
(2) K. Georgiou and H. Kroto, 1980, J. Mol. Spectrosc. 83, 94.
Calculated frequencies with uncertainties exceeding 0.1 MHz should be viewed with caution.
The experimental dipole moment is from (2).