Density Functional for Anisotropic Fluids

TL;DR

This paper introduces a new density functional for anisotropic fluids that improves the prediction of nematic-isotropic transition points in systems of hard particles, bridging existing theories for spheres and rods.

Contribution

A novel density functional that interpolates between Rosenfeld and Onsager functionals, enhancing accuracy for anisotropic fluid phase transition predictions.

Findings

Accurately predicts nematic-isotropic transition locations

Performs better than Onsager functional

Comparable to Parsons and Lee theory

Abstract

We propose a density functional for anisotropic fluids of hard body particles. It interpolates between the well-established geometrically based Rosenfeld functional for hard spheres and the Onsager functional for elongated rods. We test the new approach by calculating the location of the the nematic-isotropic transition in systems of hard spherocylinders and hard ellipsoids. The results are compared with existing simulation data. Our functional predicts the location of the transition much more accurately than the Onsager functional, and almost as good as the theory by Parsons and Lee. We argue that it might be suited to study inhomogeneous systems.