POTENTIAL-ENERGY SURFACES FOR AR-OH (X(2)PI) OBTAINED BY FITTING TO HIGH-RESOLUTION SPECTROSCOPY

Empirical potential energy surfaces for Ar interacting with OH (X2PI) are obtained by fitting to experimental results from microwave and sti mulated-emission pumping (SEP) spectra of the Ar-OH complex. The sum V (II) and difference V2 of the potentials for A' and A'' symmetry are d etermined. The sum potential is 126 cm-1 deep, which is about 24 cm-1 deeper than the ab initio CEPA potential of Degli Esposti and Werner [ J. Chem. Phys. 93, 3351 (1990)]. The equilibrium geometry is near-line ar, Ar-H-O, with a barrier to internal rotation of 44 cm-1. The potent ial satisfactorily reproduces all the parameters obtained from the SEP experiments, but not the parity doubling obtained from the microwave spectrum.