With respect to the first entry from June 2017, very extensive additional data were added to the line list. These were published by
(1) D. J. Tyree, T. W. Chapman, I. R. Medvedev, Z. Kisiel, 2022, J. Mol. Spectrosc. 390, Art. No. 111706.
The transition frequencies were judged slightly to considerably conservative and were adjusted; some of the older data were adjusted also. This is more appropriate compared to the uniform transformation in (1) via the standard error. A small number of lines with larger residuals was omitted; the number is slightly different and slightly smaller than that in (1). The initial data set was summarized in
(2) A. J. Remijan, L. E. Snyder, B. A. McGuire, H.-L. Kuo, L. W. Looney, D. N. Friedel, G. Yu. Golubiatnikov, F. J. Lovas, V. V. Ilyushin, E. A. Alekseev, S. F. Dyubko, B. J. McCall, and J. M. Hollis, 2014, Astrophys. J. 783, Art. No. 77.
Besides new millimeter data, the line list contains extensive lower frequency data from
(3) R. D. Brown, P. D. Godfrey, and J. Storey, 1975, J. Mol. Spectrosc. 58, 445.
Additional data were taken from
(4) W. Kasten and H. Dreizler, 1986, Z. Naturforsch. A 41, 1173;
and from
(5) U. Kretschmer, D. Consalvo, A. Knaack, W. Schade, W. Stahl, and H. Dreizler, 1996, Mol. Phys. 87, 1159.
Detailed ¹⁴N hyperfine splitting was resolved in (4) and (5), but has been omitted here as the molecule appears to be found best in hot molecular cores/corinos. The calculations should be accurate enough for all observational purposes. Transition frequencies with calculated uncertainties larger than 0.2 MHz should be viewed with caution.
The partition function considers the ground vibrational state only. Vibrational correction factors have been derived. Please do note the caveats ! Spin-statistical weights of the ratio 13 : 11 were omitted as they are close to 1 : 1. In v = 0, K_a + K_c even and odd would carry the weights of 13 and 11, respectively.
The dipole moment was determined in (3).