Near-dissociation expansions and dissociation energies for Mg+–(rare gas) bimers

Abstract

This paper describes the use of fits to near‐dissociation expansions (NDE’s) for performing optimum vibrational level energy extrapolations to determine diatom dissociation energies, together with realistic estimates of the uncertainties due to model‐dependence. The imposition of extended near‐dissociation theory constraints on the leading deviation from limiting near‐dissociation behavior is introduced and applied for the first time. Fits of recently determined vibrational energies for Mg⁺–Ar, Mg⁺–Kr, and Mg⁺–Xe to near‐dissociation expansions yield improved estimates of the dissociation energies and realistic predictions for the total number and extrapolated energies of upper vibrational levels for both the A ²Π and X ²Σ⁺ states. A combined analysis of the data for the A ²Π_1/2 and ²Π_3/2 states, and of the vibrationally‐dependent spin–orbit splittings, yields particularly compact internally consistent results for these systems.