The experimental data has been summarized in
(1) L. Bizzocchi, C. Degli Esposti, L. Dore, Z. Kisiel, 2008, J. Mol. Spectrosc., 251, 138.
The uncertainties employed here are somewhat closer to the implicitely used ones, which are 0.583 times the explicitely stated ones. The set of spectroscopic parameters is slightly more extensive than the one in (1). Besides original data from that work, additional data were taken from
(2) R. Pearson, A. Choplin, V. W. Laurie, 1975, J. Chem. Phys., 62, 4859.
Most of the remaining older data had been remeasured and published with greater accuracy in (1); these data were not included here. Frequencies for one rotational transition were taken from
R. D. Brown, P. D. Godfrey, A. L. Ottrey, 1980, J. Mol. Spectrosc., 81, 303.
Predictions are probably reliable throughout.
The dipole moment components were determined in (1).