The lines were taken from
(1) R. D. Brown, P. D. Godfrey, P. S. Elmes, M. Rodler, and L. M. Tack, 1985, J. Am. Chem. Soc. 107, 4112.
The number of transitions may be suffient to determine centrifugal distortion terms reliably. The correct frequency of the J = 20 – 19 transition may deviate from the experimentally determined one by more than three times the reported uncertainty. This could affect predictions above 200 GHz.
Predictions should be reliable up to about 300 to 400 GHz.
The dipole moment was assumed to agree with that of the main isotopic species.