Isobars and pitch of cholesteric phases for a chiral Gay-Berne fluid by molecular dynamic simulations

Abstract

In this work, we explore using molecular dynamics simulations, the isobars and the behaviour of the pitch as a function of temperature and density for a chiral Gay-Berne model using different parametrisations. We present two alternative and consistent methods to calculate the pitch whose dependence on temperature may increase or decrease depending on the parameters of the model. This agrees with experimental results of cholesteric liquid crystals where both positive and negative slopes have been found in the pitch versus temperature curves. We propose a qualitative explanation of this behaviour in terms of the thermal expansion and average angle between the particles.