Finite Element Method for Calculating Closest Approach of Hard Spherocylinder Fluids and the Study of Their Direct Correlation Function

We study the direct correlation function (DCF) of a classical fluid of non-spherical molecules. The components of the fluid are hard spherocylinder (SC) molecules. The required homogeneous DCF is obtained by solving Orenstein-Zernike (OZ) integral equation numerically, using the Percus-Yevich (PY) approximation and the procedure proposed by Ram and co-workers. We also obtained the closest approach between two spherocylinders by using two different methods: first, extending the algorithm proposed by Vega and Lago by introducing a new geometry and second, use the finite element procedure. Results are in agreement in two methods. The calculation is performed for various values of packing fractions of the fluid and for the aspect ratios L/D=5.0,10.0. The coefficient expansions of DCF are obtained. The results are in agreement with the other recent works.