Millimeter and submillimeter transition frequencies are from
(1) V. Lattanzi, M. Sanz-Novo, V. M. Rivilla, I. Jiménez-Serra, and P. Caselli, 2025, Front. Chem. 13, Art. No. 1720662.
The unpublished transition frequenmcies were kindly provided by the first author. trans-HNSO is about 1000 cm^–-1 (1450 K) or more higher than cis-HNSO (here just called HNSO). It is unlikely to be detected under conditions of local thermal equilibrium. Therefore, it was treated as separate species only.
The calculation should be sufficient for identifications in the ISM. Calculated transition frequencies should be viewed with caution if the calculated uncertainties exceed 0.1 MHz. ¹⁴N hyperfine splitting may matter in astronomical observations. The hyperfine parameters are from a quatum chemical calculation by
(2) H. S. P. Müller, 2023, unpublished..
The calculated splittings should be taken with slight caution. A separate hyperfine calculation is provided for J ≤ 10 below 370 GHz and with K_a ≤ 3. NOTE: The partition function takes into account the spin multiplicity of the ¹⁴N nucleus !
The dipole moment is from a quantum chemical calculation in (1).