ExoMol line lists – LXVIII. Rotation–vibration–electronic spectroscopy of potassium hydride (KH)
Year: 2026
Type: article
Abstract: ABSTRACT Comprehensive line lists for three potassium hydride (KH) isotopologues, $^{39}$KH, $^{40}$KH, and $^{41}$KH, applicable at high temperatures are presented. Ab initio potential energy curves (PECs), non-adiabatic couplings (NACs), spin-orbit curves, electronic angular momentum curves, and (transition) dipole moment curves ((T)DMCs) are generated for the X $^{1}\Sigma ^{+}$, A $^{1}\Sigma ^{+}$, B $^{1}\Pi$, C $^{1}\Sigma ^{+}$, a$\, ^{3}\Sigma ^{+}$, c$\, ^{3}\Sigma ^{+}$, and b$\, ^{3}\Pi$ states of KH using the MRCI method. Empirical energy levels are determined for the X $^{1}\Sigma ^{+}$, A $^{1}\Sigma ^{+}$ and B $^{1}\Pi$ states using the MARVEL (Measured Active Rotation Vibration Energy Levels) procedure, and are used to refine the corresponding ab initio PECs of X $^{1}\Sigma ^{+}$, A $^{1}\Sigma ^{+}$ and B $^{1}\Pi$. These PECs and (T)DMCs are used to calculate energies, Einstein A coefficients, lifetimes and partition functions up to 10 000 K covering wavenumbers below 40 000 cm$^{-1}$ ($\ge 250$ nm) and rotational excitations with $J \le 130$. Calculated energies and state lifetimes are generally in good agreement with experimental values. Emission to unbound X $^{1}\Sigma ^{+}$ states contributes significantly to lifetimes of A $^{1}\Sigma ^{+}$ rovibronic states. This study should facilitate detections of KH in exoplanet and stellar atmospheres. The Khan line lists are available from the ExoMol data base at www.exomol.com.
Institution: University College London
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,046
OpenAlex ID: W7162191941