The transition frequencies were summarized by
(1) R. Chabazian, M.-A. Martin-Drumel, and O. Pirali, 2024, J. Phys. Chem. A 128, 370.
Included in the line list are microwave data from
(2) Y. Endo and M. Nakajima, 2014, J. Mol. Spectrosc. 301, 15;
millimeter wave data from
(3) Y. Endo, S. Saito, and E. Hirota, 1985, J. Chem. Phys. 83, 2026;
along with combination differences from
(4) Y. G. Utkin, J.-X. Han, F. Sun, H.-B. Chen, G. Scott, and R. F. Curl, 2003, J. Chem. Phys. 118, 10470.
The parameter set is slightly different from the one in (1). The molecule may be found best in cold or luke-warm sources. Therefore, HFS splitting is calculated for all H nuclei. The calculations should be sufficiently accurate and extensive for all observational purposes. The default entry has five quantum numbers, the fourth one being an aggregate spin number. A calculation with the full set of quantum numbers is also available. Transition frequencies with calculated uncertainties exceeding 0.2 MHz should be viewed with caution.
The dipole moment is from a quantum chemical calculation in (2).