MICROWAVE-SPECTRA OF THE NE-N-2 VAN-DER-WAALS COMPLEX - EXPERIMENT AND THEORY

High-resolution microwave spectra of the ground state Ne-20-N-14(2), N e-20-N-15(2), Ne-22-N-14(2), and Ne-22-N-15(2) Van der Waals complexes , involving rotational levels up to J=4, are reported. Interpretation and assignment of the observed transitions were made by combining resu lts of measurements and theoretical predictions of the MW line positio ns in terms of available empirical potential energy surfaces and of a new high-level ab initio potential energy surface. The deviations of t he calculated MW spectra from those observed experimentally are more u niform for the ab initio potential surface than they are for the empir ical potential surfaces, allowing for reduction of the deviations to w ithin 0.07% for all isotopomers by a single-parameter scaling of the n b initio potential energy surface. The scaled Ne-N-2 interaction poten tial was used to predict the MW line positions for the transitions J'- J ''=3-2, 4-3 for all species. A simple procedure is proposed to impro ve the ab initio results for atom-diatom systems on the basis of atom- atom interaction components. (C) 1998 American Institute of Physics. [ S0021-9606(98)01437-8].