ExoMol line lists XXVIII: The rovibronic spectrum of AlH

Abstract

A new line list for AlH is produced. The WYLLoT line list spans two electronic states $X{}^1{\Sigma }^{+}$ and $A{}^1\Pi$. A diabatic model is used to model the shallow potential energy curve of the $A{}^1\Pi$ state, which has a strong pre-dissociative character with only two bound vibrational states. Both potential energy curves are empirical and were obtained by fitting to experimentally derived energies of the $X{}^1{\Sigma }^{+}$ and $A{}^1\Pi$ electronic states using the diatomic nuclear motion codes Level and Duo. High temperature line lists plus partition functions and lifetimes for three isotopologues ${}^{27}$AlH, ${}^{27}$AlD and ${}^{26}$AlH were generated using ab initio dipole moments. The line lists cover both the $X$--$X$ and $A$--$X$ systems and are made available in electronic form at the CDS and ExoMol databases.