The experimental data were taken from
(1) R. M. Lees, 1971, Can. J. Phys., 49, 367;
and from
(2) S. B. Bteich, B. Tercero, J. Cernicharo, R. A. Motiyenko, L. Margulès, and J.-C. Guillemin, 2016, Astron. Astrophys., 592, Art. No. A43.
The uncertainties used for the data from (2) were those implicitely reported, which are smaller than the explicitely reported ones by a factor of 1.5.
Predictions with uncertainties exceeding 0.3 MHz should be viewed with caution. Carbonyl nitrile is rather heavy and has a low volatility. Therefore, we expect predictions to be sufficient for astronomical searches at present. Spin-statistics of 1 : 2 have been considered for transitions with K_a + K_c being odd and even, respectively.
The partition function refers to the ground state only. Vibrational correction factors will be provided.
¹⁴N hyperfine splitting may be resolvable at low values of J and possibly at the highest K. Therefore, predictions with hyperfine splitting have been provided up to J = 10 and up to 120 GHz; along with appropriate partition function values.
The dipole moment was determined in (1).