The microwave and millimeter wave data were reported by
(1) J. Demaison, A. Dubrulle, D. Boucher, J. Burie, and V. Typke, 1979, J. Mol. Spectrosc. 76, 1.
Submillimeter data were bublished by
(2) F. X. Brown, J. Cosleou, D. Dangoisse, J. Demaison, and G. Wlodarczak, 1989, J. Mol. Spectrosc. 134, 234.
A D_K value was derived from a force field calculation by
(3) J. L. Duncan, D. C. McKean, F. Tullini, G. D. Nivellini, and J. Prez Peña, 1978, J. Mol. Spectrosc. 69, 123.
Using that value, A was determined by
(4) S. Alanko, M. Koivusaari, R. Paso, and R. Anttila, 2001, J. Mol. Spectrosc. 207, 89.
Additional higher order parameters were estimated from the main isotopic species published in
(5) H. S. P. Müller, L. R. Brown, B. J. Drouin, J. C. Pearson, I. Kleiner, R. L. Sams, K. Sung, M. H. Ordu, and F. Lewen,
2015, J. Mol. Spectrosc. 312, 22.
No uncertainties were given in (1) or (2), but they could be evaluated easily. Laser sideband measurements from (2) were not merged.
The calculations are reliable for observational purposes.
At low temperatures, it may be necessary to discern between A-CD₃CN and E-CD₃CN. The A state levels are described by K = 3n, those of E state by K = 3n ± 1. The nuclear spin-weight ratio is 11 : 22 : 16 for A-CD₃CN with K = 0, K > 0, and for E-CD₃CN, respectively. The J_K = 1₁ level is the lowest E state level. It is 2.91 cm^–1 above ground.
The dipole moment was reported by
(6) A. P. Steiner and W. Gordy, 1966, J. Mol. Spectrosc. 21, 291.