Local structure in nematic and isotropic liquid crystals

Abstract

By computer simulations of systems of ellipsoids, we study the influence of the isotropic/nematic phase transition on the direct correlation functions (DCF) in anisotropic fluids. The DCF is determined from the pair distribution function by solving the full Ornstein-Zernike equation, without any approximations. Using a suitable molecular-fixed reference frame, we can distinguish between two qualitatively different contributions to the DCF: One which preserves rotational invariance, and one which breaks it and vanishes in the isotropic phase. We find that the symmetry preserving contribution is barely affected by the phase transition. However, symmetry breaking contributions emerge in the nematic phase and may become quite substantial. Thus the DCF in a nematic fluid is not rotationally invariant. In the isotropic fluid, the DCF is in good agreement with the prediction of the Percus-Yevick theory.

to appear in J. Chem. Phys

References in corpus (3)

• Density Functional for Anisotropic Fluids
• Surface anchoring on layers of grafted liquid-crystalline chain molecules: A computer simulation
• Surface anchoring on liquid crystalline polymer brushes

Cited by in corpus (5)

• Pair correlation functions in nematics, free-energy functional and isotropic-nematic transition
• Nematic-Isotropic Interfaces Under Shear: A Molecular Dynamics Simulation
• A density functional theory study of the confined soft ellipsoid fluid
• Pair Correlation Functions and a Free-Energy Functional for the Nematic Phase
• Crystallization of Simple Fluids: Relative Stability of f.c.c. and b.c.c Structures