The entry was substantially modified from the first entry dated Sep. 2000. Transition frequencies were reported by
(1) S. Yamamoto, S. Saito, M. Guélin, J. Cernicharo, H. Suzuki, and M. Ohishi, 1987, Astrophys. J. 323, L149.
Additional transition frequencies with hyperfine splitting were taken from
(2) 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). Transition frequencies with calculated uncertainties exceeding 0.2 MHz should be viewed with caution.
The vibrational energy was estimated as two times the energy of v₇ = 1 taken from
(3) F. J. Mazzotti, R. Raghunandan, A. M. Esmail, M. Tulej, and J. P. Maier, 2011, J. Chem. Phys. 134, Art. No. 164303.
The new 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.