The transition frequencies were reported by
(1) H. S. P. Müller, A. Belloche, F. Lewen, and S. Schlemmer, 2026, ACS Earth Space Chem., accepted.
The purely K-dependent terms A and D_K were assumed to agree with those of the main isotopolog, see e041505.cat.
The transition frequencies should be viewed with caution if the calculated uncertainties exceed 0.1 MHz.
The partition function values below refer to the ground vibrational state only. Vibrational correction factors have been derived in the harmonic approximation.
At low temperatures, it may be necessary to discern between A-CH₃¹³C¹⁵N and E-CH₃¹³C¹⁵N. The A state levels are described by K = 3n, those of E state by K = 3n ± 1. The nuclear spin-weight ratio is 2 : 1 for A-CH₃¹³C¹⁵N with K > 0 and all other states, respectively. The J_K = 1₁ level is the lowest E state level. It is 5.5711 cm^–1 above ground.
The dipole moment was assumed to agree with the one of CH₃C¹⁵N reported by
(2) A. Mito, J. Sakai, and M. Katayama, 1984, J. Mol. Spectrosc. 103, 26.