The observed transitions were taken from
(1) L. Bonah, S. Schlemmer, J.-C. Guillemin, M.E. Harding, and S. Thorwirth, 2024, J. Phys. Chem. A 128, 4859
No internal rotation splitting was observed for the data from (1).
Calculations with uncertainties exceeding 0.2 MHz should be viewed with caution.
Energy levels up to J = 200 and K_a = 100 have been considered in the calculation of the partition function. This is sufficient up to 300 K.
The dipole moments are taken from quantum-chemical calculations performed at the ae-CCSD(T)/cc-pwCVQZ level presented in (1).
Corrections to the partition due to low-lying vibrationally excited states may be required. The four fundamental modes below 500 cm^–1 are at 165 cm^–1, 205 cm^–1, 326 cm^–1, and 479 cm^–1 (values are from (1) at ANO1 level).
Typical patterns for interactions with probably the energetically-lowest vibrationally excited state were seen for K_a = 18, K_a = 22, and K_a ≥ 26. Thus, assignments from (1) are limited to transitions with K_a < 26; in addition, 25 transitions were rejected from the fit due to their residuals.