ExoMol line lists - I. The rovibrational spectrum of BeH, MgH and CaH in theX ²Σ⁺state

Abstract

Accurate line lists for three molecules, BeH, MgH and CaH, in their ground electronic states are presented. These line lists are suitable for temperatures relevant to exoplanetary atmospheres and cool stars (up to 2000 K). A combination of empirical and ab initio methods is used. The rovibrational energy levels of BeH, MgH and CaH are computed using the programs level and dpotfit in conjunction with ‘spectroscopic’ potential energy curves (PECs). The PEC of BeH is taken from the literature, while the PECs of CaH and MgH are generated by fitting to the experimental transition energy levels. Both spin‐rotation interactions (except for BeH, for which it is negligible) and non‐adiabatic corrections are explicitly taken into account. Accurate line intensities are generated using newly computed ab initio dipole moment curves for each molecule using high levels of theory. Full line lists of rotation–vibration transitions for 9BeH, 24MgH, 25MgH, 26MgH and 40CaH are made available in an electronic form as supporting information to this paper and at http://www.exomol.com.

ExoMol molecular line lists – XIII. The spectrum of CaO

“…CaO is one of a number of molecules which may be observable constituents of hot, rocky exoplanets. The ExoMol project has already provided linelists for a number of other, similar molecules including MgH and CaH (Yadin et al 2012), SiO (Barton et al 2013), NaCl and KCl (Barton et al 2014), AlO (Patrascu et al 2015), ScH (Lodi et al 2015) and NaH (Rivlin et al 2015). A number of other potentially important species, including VO (McKemmish et al 2015), TiO, TiH, NiH and CrH (Gorman et al 2016), are currently being studied.…”

ExoMol: molecular line lists for exoplanet and other atmospheres

“…In more complicated cases it will be necessary to consider the coupling between different electronic states explicitly in the calculation. Work on diatomic line lists is actively underway with line lists for the X 2 Σ + states of BeH, MgH and CaH (Yadin et al 2012).…”

ExoMol molecular line lists – X. The spectrum of sodium hydride

“…As with other diatomic systems studied as part of the ExoMol project (Yadin et al 2012;Barton et al 2013Barton et al , 2014Yorke et al 2014;Patrascu et al 2015), we treated NaH using both ab initio and experimental data. Walji et al (2015) used a direct potential fit analysis to generate accurate potential energy curves for the ground and first singlet excited states of NaH (X 1 Σ + g and 'Avoided Crossing' A 1 Σ + g ).…”