Ab Initio Potential Energy Surface and Vibration–Rotation Energy Levels of Aluminum Monohydroxide

Abstract

The potential energy surface and vibration−rotation energy levels of aluminum monohydroxide in the X ̃1A′ electronic state have been determined from ab initio calculations. The equilibrium configuration of the AlOH molecule was found to be bent, although with a wide AlOH angle of 163°and a small barrier to linearity of just 4 cm −1 . The AlOH molecule was definitely confirmed to be quasilinear. The predicted spectroscopic constants of the AlOH, AlOD, 26 AlOH, and Al 18 OH isotopologues can be useful in a future analysis of high-resolution vibration−rotation spectra of these species.