Monte Carlo Simulation of the Rotator Phase of Cyclohexane

Abstract

The reorientational behaviour of cyclohexane molecules in the rotator phase has been investigated with a Monte Carlo simulation on a system of 108 molecules in a cubic box with periodic boundary conditions. Different starting configurations have been tested, including also a special model where the molecules are aligned parallelly to the four cubic threefold axes. This model is characterized by a low potential energy. The discrete molecular orientations of this model are maintained at 195 K, that is, in the immediate neighbourhood to the low-temperature solid 11-solid I transition. At higher temperatures no preferred orientations can be detected, irrespective of the employed starting set up. Both the molecular three-fold axes and the angles between them of neighbouring molecules are distributed randomly. Therefore the Frenkel model of a discrete number of preferred orientations is discounted.