Fluids of hard ellipsoids: Phase diagram including a nematic instability from Percus-Yevick theory

TL;DR

This paper uses Percus-Yevick theory to analyze the phase diagram of hard ellipsoids, revealing conditions for nematic instability and comparing results with simulations and density functional theory.

Contribution

It provides a detailed phase diagram for hard ellipsoids including a criterion for nematic instability using Percus-Yevick theory.

Findings

Identifies a nematic instability criterion in hard ellipsoid fluids.

Calculates the equilibrium phase diagram for hard ellipsoids.

Results agree well with Monte Carlo simulations and density functional theory.

Abstract

An important aspect of molecular fluids is the relation between orientation and translation parts of the two-particle correlations. Especially the detailed knowledge of the influence of orientation correlations is needed to explain and calculate in detail the occurrence of a nematic phase. The simplest model system which shows both orientation and translation correlations is a system of hard ellipsoids. We investigate an isotropic fluid formed of hard ellipsoids with Percus-Yevick theory. Solving the Percus-Yevick equations self-consistently in the high density regime gives a clear criterion for a nematic instability. We calculate in detail the equilibrium phase diagram for a fluid of hard ellipsoids of revolution. Our results compare well with Monte Carlo Simulations and density functional theory.