Integral equation theory for molecular fluids: effect of quadrupolar interactions

The Percus–Yevick (PY) and the hypernetted chain (HNC) integral equations have been solved for fluids of hard ellipsoids of a revolution represented by a hard Gaussian overlap model and for fluids of quadrupolar hard Gaussian overlap model. The structural and thermodynamic properties of the isotropic phase are discussed in detail. Ellipsoids with length-to-width ratios of 1.792, 3.0, 4.0 and 5.0 are considered and results are reported for different densities and quadrupole moments. It is shown that both the HNC and PY theories are in reasonable agreement with the computer simulation results.