The v₅ = 1 experimental frequencies have been reported by
(1) P. D. Mallinson and R. L. de Zafra, 1978, Mol. Phys. 36, 827; and by
(2) S. Thorwirth, H. S. P. Müller, and G. Winnewisser, 2001, Phys. Chem. Chem. Phys. 3, 1236.
The v₇ = 3 state is about 3.75 cm^–1 lower than v₅ = 1. Strong interactions occur between v₅ = 1 and v₇ = 3 for l = 1^f in both states at J = 49; and for l = 1^e at J = 58. The l = 1^e substate is the one occuring generally at lower frequencies. The present parameter set differs slightly from the one in (2).
The state numbers 0 and 1 designate v₅ = 1 and v₇ = 3, respectively.
The ¹⁴N hyperfine splitting has not been considered in the present entry. Note: The partition function does not include vibrational contributions. However, information on vibrational contributions to the partition function is available.
The dipole moments were assumed to be the same as for the main species, v₅ = 1 / v₇ = 3, see e051508.cat.