A MODEL FOR THE STUDY OF THE STRUCTURE OF HARD MOLECULAR FLUIDS

A model previously introduced to study the structure and thermodynamic s of fluids of anisotropic molecules with orientations restricted to c ertain discrete directions is generalized and used to study normal mol ecular fluids in which the molecules can rotate freely. The basis is a n ansatz for the direct correlation function which depends on the geom etry of two molecules. The method leads to the Percus-Yevick solution for hard spheres and to Onsager's solution in the limit of long needle s. In this paper it is applied to fluids comprising hard spherocylinde rs and to fluids of hard ellipsoids.