Effect of direct correlation functions on elastic constants of molecular liquids

Abstract

We study the effect of molecule sizes and intermolecular interactions on Frank elastic constants in nematic liquid crystals with ellipsoid of revolution molecules. We use the Poniewierski-Stecki equations which depend on direct correlation functions of ellipsoid molecules and apply the new direct correlation function using the Marko method and contact distance of ellipsoids. The elastic constants for different molecular elongations, using repulsive interaction of hard ellipsoids of revolution and attractive dispersion interaction are calculated. These elastic constants are deduced from a new direct correlation function. It is shown that they are in good agreement with Singh and singh results and qualitatively corresponds to the experiments. The ratios of calculated elastic constants are in agreement with the available experimental results.