			15min:

ACCURATE POTENTIAL ENERGY CURVES FOR THE GROUND ELECTRONIC STATES OF NeH⁺ AND ArH⁺.

JOHN A. COXON, Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3; PHOTOS G. HAJIGEORGIOU, Department of Life and Health Sciences, University of Nicosia, Nicosia 1700, Cyprus.

All available microwave and infrared spectroscopic line positions for the ground electronic states of the molecular cations NeH⁺ and ArH⁺ were employed in a direct potential fitting procedure to determine compact analytical potential curves and radial functions describing breakdown of the Born-Oppenheimer approximation. For NeH⁺, 17 adjustable parameters were required to represent a total of 183 line positions for 4 isotopologues, whereas for ArH⁺, 23 adjustable parameters were required to represent 440 line positions for 6 isotopologues. The MLR3 potential energy functional form was employed, taking full account of the proper 1/r⁴ limiting long-range dependence of the ion-atom dispersion energy interactions. Accurate vibrational energies, rotational constants and centrifugal distortion constants have been calculated for both diatomic cations.