Abstract: The diffusion coefficients and interaction viscosities for Ar in N₂ are calculated based on physical dynamics theory, by employing quantum mechanical IOSA approximation and Ar-N₂ effective interaction potential. The calculation results are in good agreement with the experimental values, and better than those of Gianturco and others. T he calculation interaction viscosity values are very close to experimental ones in the caluculation range.

Key words: diffusion coefficient, interaction viscosity, Ar-N₂ interaction potential, Numerov method