THE STRUCTURE OF A CONFINED FLUID OF CYLINDRICAL MOLECULES - SIMULATION AND THEORY

The structure of a model fluid of hard cylindrical molecules with their axes restricted to lie along one of three mutually orthogonal directions and confined to a slit is studied by means of a Monte Carlo simulation and by theories based upon PY and HNC approximations. The theories depend upon the direct correlation function of the homogeneous fluid which is approximated by a linear combination of the Mayer function and the overlapping volume of two cylinders. It is found that, for a range of ratios of length l to diameter d of thc cylinders and for a range of packing fractions, the theories give good agreement with the simulation. Generally, the HNC theory gives better agreement than PY although, as for isotropic fluids, both are poor very close to a wall.