Hard body model for chiral nematic liquid crystals

Abstract

A stability analysis, expressed within the framework of a density functional theory, is employed to calculate the wavelength of the pitch of a chiral nematic liquid crystal. The chiral bodies are represented by a hard convex twisted ellipsoidal core, with and without an encircling isotropic square well. In the present chiral particle model, equipped with an approximate two body direct correlation function, the chiral pitch was found to be density and temperature independent with values in the visible region of the spectrum. Long range potential softness can account for the increase of the pitch with decreasing temperature. The relationship of the present theory with those of previous workers is also explored.