The experimental data was taken from by
(1) W. M. Tolles and W. D. Gwinn, 1965, J. Chem. Phys. 42, 2253,
(2) S. Skaarup, PhD thesis, Lic. Tech. Copenhagen, 1972,
(3) S. Thorwirth, H. S. P. Müller, and G. Winnewisser, 2000, J. Mol. Spectrosc. 199, 116,
and from
(4) S. Thorwirth, R. Gendriesch, H. S. P. Müller, F. Lewen, and G. Winnewisser, 2000, J. Mol. Spectrosc. 201, 323.
With respect to the March 2000 entry, the main entry does not consider ¹⁴N hyperfine structure. The version number has been retained. Sizable ¹⁴N quadrupole splitting has been observed for low values of J and K_a in the microwave and millimeter wave regions. Therefore, predictions with hyperfine structure are available up to 120 GHz and J = 10.
NOTE: as previously, the partition function does take into account g_I(14N) = 3 !
The predictions should be reliable throughout.
The dipole moment was determined in (3).