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　He-2,　Ne-2,　Ar-2,　and　Kr-2　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　D-e,　and　the　dispersion　coefficients　C-6-　C-10.　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.