Determination of Molecular Quadrupole Moments from Viscosities and Second Virial Coefficients

Gas viscosity data for nine quadrupolar molecules are analyzed using calculated collision integrals for the 12–6−5 potential. The parameters of the spherical component of the potential are obtained from the viscosity data, and then used in conjunction with second virial coefficient data to determine the quadrupole moments and ``shape'' parameters of the molecules. The quadrupole moments obtained are very reasonable, and further improvement along these lines will probably depend on a better understanding of the nonspherical components of the repulsive part of the potential.