A reliable new three-dimensional potential energy surface is obtained
for the H-2-Ar system using an exchange-coulomb potential model with f
ive parameters determined empirically from a least-squares fit to expe
rimental data. This surface fully accounts for new high resolution IR
data, virial coefficients, and vibrational transition pressure-shiftin
g coefficients used in the analysis, and yields excellent predictions
of elastic and inelastic scattering cross sections and hyperfine trans
ition intensities not included in the analysis. Quantitative compariso
ns with the best previous empirical potential and a high quality fully
ab initio potential are also presented. (C) 1996 American Institute o
f Physics.