Exchange-Coulomb potential energy surfaces and related physical properties for Ne-N2

An exchange-Coulomb (XC) potential energy model is developed for the Ne-N₂ interaction. The construction of this new potential energy surface is based on recent results for the Heitler-London interaction energy, the long range dispersion energies, and the microwave spectra of the dimer. The adjustable parameters in the final XC1 potential energy surface have been determined by fitting the frequencies of three representative lines of the microwave spectrum for the two isotopomers ²⁰Ne-¹⁴N₂ and ²⁰Ne-¹⁵N₂ while simultaneously maintaining agreement with the experimental second virial coefficient data obtained with the initial (unadjusted XC0 potential. With no further adjustment of parameters, the final XC potential reproduces, within 0.005%, the frequencies of the 34 microwave transitions studied experimentally for four isotopomers of Ne-N₂. Excellent agreement with experiment is obtained also for the binary diffusion, the interaction viscosity, and the mixture viscosity (for all compositions) coefficients for all temperatures. Agreement with experiment for the relaxation cross-sections associated with viscomagnetic effects, and with the pressure broadening of depolarized Rayleigh light scattering, is very good given the level of computation used for the calculations and the accuracy with which some of these cross-sections currently can be determined from experimental data. Comparisons are made with predictions calculated from the three best literature potential energy surfaces or Ne-N₂. The final XC1 potential energy surface is overall the most reliable potential energy for this van der Waals complex to date. The flexibility still inherent in this potential can be exploited, if required, in future studies of the Ne-N₂ system.