Transition frequencies were reported by
(1) A. L. Cooksy, C. A. Gottlieb, T. C. Killian, P. Thaddeus, N. A. Patel, K. H. Young, and M. C. McCarthy, 2015, Astrophys. J. Suppl. Ser. 216, Art. No. 30.
The parameter set and the parameter values differ somewhat from those in (2). This vibrational state is perturbed considerably, especially above 200 GHz. The perturber is not yet known. Transition frequencies above 365 GHz should be viewed with very great caution; those up to that frequency should be reasonable because effective parameters reproduce the experimental data quite well.
The vibrational energy was assumed to agree with an unassigned feature in
(2) F. J. Mazzotti, R. Raghunandan, A. M. Esmail, M. Tulej, and J. P. Maier, 2011, J. Chem. Phys. 134, Art. No. 164303.
This energy is close to the vibrational energy from a quantum chemical calculation.
Note: the energy chosen is 372.7, it was supposed to be 377.8.
The dipole moment was assumed to be the same as in the X ²Σ⁺ ground vibrational state, see e049503.cat. This assumption may be reasonable.
The partition function of the main species takes into account all states presently available in the CDMS. It is converged fairly well up to about 150 K. Vibrational contributions to the partition function are also available. These should be viewed cautiously because of several estimates concerning vibrational energies.