The experimental laboratory frequencies were reported in
(1) J. J. Christiansen, 2005, J. Mol. Spectrosc. 231, 131;
and in
(2) M. Winnewisser, I. R. Medvedev, F. C. DeLucia, E. Herbst, J. Koput, K. V. L. N. Sastry, and R. A. H. Butler, 2005, Astrophys. J. Suppl. Ser. 159, 189.
The dipole moment was reported in (1).
The ¹⁴N hyperfine splitting may be resolvable at lower frequencies or at lower quantum numbers. Therefore, a separate calculation with hyperfine structure is available up to 180 GHz and with J up to 10. In the general entry, the spin-multiplicity of the ¹⁴N nucleus was not considered in the calculation of the partition function. Because of the two N nuclei, the partition function values have to be multiplied with 9 when hyperfine structure is considered.
Transition frequencies with predicted uncertainties of considerably more than 1 MHz should be viewed with caution.