Direct determination of the intermolecular interaction contribution to the refractive index of carbon dioxide and sulfur hexafluoride

The experimental values of the first and the second refractivity virial coefficients have been determined for carbon dioxide and sulfur hexafluoride. In the case of carbon dioxide the experimental second refractivity virial coefficient is less than the classically calculated theoretical value and for sulfur hexafluoride the experimental value is larger than the theoretical value. Combined with the earlier values of the second dielectric virial coefficient, the present experimental results agree well with the integrated collision induced absorption in the infrared and the far infrared.