The transition frequencies were reported in
(1) J. Tang and S. Saito, 1995, Astrophys. J. 451, L93.
See also
(2) L. Margulès, F. Lewen, G. Winnewisser, P. Botschwina, and H. S. P. Müller, 2003, Phys. Chem. Chem. Phys. 5, 2770.
The electric dipole moment was assumed to be the same as for the main species (e45506.cat).