ExoMol line lists-LVI. The SO line list, MARVEL analysis of experimental transition data and refinement of the spectroscopic model

Abstract

A semi-empirical IR/Vis line list, SOLIS, for the sulphur monoxide molecule 32S16O is presented. SOLIS includes accurate empirical rovibrational energy levels, uncertainties, lifetimes, quantum number assignments, and transition probabilities in the form of Einstein A coefficients covering the, and systems and wavenumber range up to 43 303.5 cm-1 (≥230.93 nm) with J ≤ 69. SOLIS has been computed by solving the rovibronic Schrödinger equation for diatomics using the general purpose variational code Duo and starting from a published ab initio spectroscopic model of SO (including potential energy curves, coupling curves, (transition) dipole moment curves) which is refined to experimental data. To this end, a database of 50 106 experimental transitions, 48 972 being non-redundant, has been compiled through the analysis of 29 experimental sources, and a self-consistent network of 8558 rovibronic energy levels for the X, a, b, A, B, and C electronic states has been generated with the marvel algorithm covering rotational and vibrational quantum numbers J ≤ 69 and v ≤ 30 and energies up to 52 350.40 cm-1. No observed transitions connect to the (v = 0) state which is required to model perturbations correctly, so we leave fitting the and state UV model to a future project. The SO line list is available at ExoMol from www.exomol.com. © 2023 The Author(s) The Author(s) 2022. Published by Oxford University Press on behalf of Royal Astronomical Society.