An isotopic independent fit was published in
(1) J. L. Doménech, O. Asvany, C. R. Markus, S. Schlemmer, and S. Thorwirth, 2020, J. Mol. Spectrosc. 374, Art. No. 111375.
Some higher order parameters were evaluated in comparison to the neutral CN molecule by
(2) H. S. P. Müller, 2023, unpublished.
Rotational transition frequencies were reported by
(3) S. Thorwirth, P. Schreier, T. Salomon, S. Schlemmer, and O. Asvany, 2019, Astrophys. J. Lett. 882, Art. No. L6.
Rovibrational transition frequencies were taken from (1).
Various Combination differences were derived in (1) from
(4) A. Douglas and P. M. Routly, 1954, Astrophys. J. 119, 303.
The calculations should be sufficiently accurate throughout. Since rotational transitions are presumably observable in cold or lukewarm sources, the calculations are provided with ¹⁴N hyperfine splitting.
The ground state dipole moment was taken from a quantum chemical calculation in
(5) R. Polák and J. Fišer, 2002, Spectrochim. Acta A 58, 2029.