Transport Properties of Quadrupolar Gases

Abstract

Collision integrals for quadrupolar gases are computed on the assumption of fixed relative orientation per collision, with a 12–6−5 potential model, for a range of reduced temperatures and reduced quadrupole moments. The quadrupole effects on diffusion and viscosity are small, but not completely negligible if one wants accurate values for the parameters of the spherically symmetric component of the potential. These values are needed to obtain quadrupole moments from properties like second virial coefficients, which are more sensitive to quadrupole effects. Thermal‐diffusion factors are the most strongly affected of the transport coefficients; the presence of quadrupolar intermolecular forces can wipe out the thermal‐diffusion inversion temperatures.