The direct determination of pair potential energy functions for mixed interactions: Ar-Kr

Measurements of the viscosity coefficients for argon-krypton gas mixtures over the temperature range 120–1600 K are inverted to give the pair potential energy function for Ar-Kr. The inversion procedure requires an estimate of the well-depth parameter ε/k and a method for its determination using second virial coefficient data is described. The resulting Ar-Kr potential function has characteristic parameters ε/k=165 K, σ=0·348 nm and r m=0·3902 nm. The conformality of this potential with those for the like-molecule interactions, and the value of parametric combining rules for this system are also investigated.