SIMBAD references

Line lists for the sulphur-containing molecules SH (the mercapto radical) and NS are computed as part of the ExoMol project. These line lists consider transitions within the X²Π ground state for ³²SH, ³³SH, ³⁴SH,³⁶SH and, ³²SD, and ¹⁴N³²S, ¹⁴N³³S, ¹⁴N³⁴S, ¹⁴N³⁶S, and ¹⁵N³²S. Ab initio potential energy (PEC) and spin-orbit coupling (SOC) curves are computed and then improved by fitting to experimentally observed transitions. Fully ab initio dipole moment curves (DMCs) computed at high level of theory are used to produce the final line lists. For SH, our fit gives a root-mean-square (rms) error of 0.03 cm^–1 between the observed (v_max = 4, J_max = 34.5) and calculated transitions wavenumbers; this is extrapolated such that all X²Π rotational-vibrational-electronic (rovibronic) bound states are considered. For ³²SH the resulting line list contains about 81 000 transitions and 2300 rovibronic states, considering levels up to v_max = 14 and J_max = 60.5. For NS the refinement used a combination of experimentally determined frequencies and energy levels and led to an rms-fitting error of 0.002 cm^–1. Each NS-calculated line list includes around 2.8 million transitions and 31 000 rovibronic states with a vibrational range up to v = 53 and rotational range up to J = 235.5, which covers up to 23 000 cm^–1. Both line lists should be complete for temperatures up to 5000 K. Example spectra simulated using this line list are shown and comparisons made to the existing data in the CDMS data base. The line lists are available from the CDS (http://cdsarc.u-strasbg.fr) and ExoMol (www.exomol.com) data bases.