An empirical potential energy function for the interactions between rare gas atoms

A new potential model was developed in this work by the modification of the repulsive part of the Tang-Toennies model. The proposed potential function was used in this work to investigate the interactions between both like and unlike rare gas atoms. The considered systems are He2, Ne2, Ar2, and Kr2 for the like interactions and HeNe, HeAr, and HeKr for the unlike interactions. The potential parameters in the repulsive part of each system were determined from the recent literature values of the equilibrium distance Re, the well depth De, and the dispersion coefficients C6-C10. Accurate potential energies available in the literature were compared with the modified potential model and the original Tang-Toennies model. Although both potential energy functions show the same performance in the attractive region and the well-depth region, the proposed potential model can provide a more realistic repulsive wall than the Tang-Toennies model. Since the transport properties of low-density gases are sensitive to the potential energies at small intermolecular distances, the viscosity and thermal conductivity computed in this work were compared with the recommended experimental data in the literature to further verify the quality of the modified potential energy function