Knowledge Bank

Alkali hydride diatomic molecules have long been the object of spectroscopic studies., 153-187 (1991).} However, their small reduced mass makes them species for which the conventional semiclassical-based methods of analysis tend to have the largest errors. To date, the only quantum-mechanically accurate direct-potential-fit (DPF) analysis for one of these molecules was the one for LiH reported by Coxon and Dickinson.\ {\bf 121}, 8378 (2004).} The present paper extends this level of analysis to NaH, and reports a DPF analysis of all available spectroscopic data for the $A1\Sigma +-X1\Sigma +$ system of NaH which yields analytic potential energy functions for these two states that account for those data (on average) to within the experimental uncertainties.