Abstract
An empirical correlation for the third virial coefficient of nonpolar gases is developed. The correlation requires a knowledge of the critical temperature, critical pressure and acentric factor of the compounds for the prediction of third virial coefficients in the absence of experimental data. The use of the correlation for mixtures of nonpolar gases, including quantum gases, requires one binary parameter for each binary interaction. Predictions are in good agreement with reported experimental data and with the values obtained with existing correlations.