ExoMol line lists – XLI. High-temperature molecular line lists for the alkali metal hydroxides KOH and NaOH

Abstract

ABSTRACT Potassium hydroxide (KOH) and sodium hydroxide (NaOH) are expected to occur in the atmospheres of hot rocky super-Earth exoplanets but a lack of spectroscopic data is hampering their potential detection. Using robust first-principles methodologies, comprehensive molecular line lists for KOH and NaOH that are applicable for temperatures up to T = 3500 K are presented. The KOH OYT4 line list covers the 0–6000 cm−1 (wavelengths λ > 1.67 µm) range and comprises 38 billion transitions between 7.3 million energy levels with rotational excitation up to J = 255. The NaOH OYT5 line list covers the 0–9000 cm−1 (wavelengths λ > 1.11 µm) range and contains almost 50 billion lines involving 7.9 million molecular states with rotational excitation up to J = 206. The OYT4 and OYT5 line lists are available from the ExoMol database at www.exomol.com and should greatly aid the study of hot rocky exoplanets.