Transition frequencies were taken from
(1) B. Heyne, M. Fatima, H. S. P. Müller, J.-C. Guillemin, P. Misra, and S. Schlemmer, 2026, Phys. Chem. Chem. Phys. 28, to be resubmitted.
The calculated transition frequencies are deemed to be accurate enough for observational astronomy. Frequencies with uncertainties larger than 0.1 MHz should be viewed with caution.
The partition function values below refer to the ground vibrational state only. Vibrational correction factors can be derived for the main isotopolog in the harmonic approximation.
The dipole moment components are from a quantum chemical calculation in (1).