The experimental data have been summarized in
(1) D. Alberton, L. Bizzocchi, N. Jiang, M. Melosso, V. M. Rivilla, A. Pietropolli Charmet, B. M. Giuliano, P. Caselli, C. Puzzarini, S. Alessandrini, L. Dore, I. Jimenez-Serra and J. Martin-Pintado, 2023, Astron. Astrophys. 669, A93,
including results from previous studies by
(2) R.E. Penn, 1978, J. Mol. Spectrosc. 69, 373-382;
(3) R.D. Brown, P.D. Godfrey, and D.A. Winkler, 1981, Chem. Phys. 59, 243-247.
Transitions with frequency uncertainties exceeding 200 kHz should be viewed with some caution.
The partition function takes into account the spin degeneracy of ¹⁴N.
Frequency predictions with hyperfine structure are available up to J = 60 and 400 GHz.
The experimental dipole moment components were reported in (2).
Vibrational correction factors have been derived in the harmonic approximation for a posteriori corrections of the column densities.