Computer simulation studies of anisotropic systems. XXX. The phase behavior and structure of a Gay–Berne mesogen
- 8 April 1999
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 110 (14), 7087-7108
- https://doi.org/10.1063/1.478563
Abstract
The Gay–Berne potential is proving to be a valuable model with which to investigate the behavior of liquid crystals using computer simulation techniques. The potential contains four independent parameters which control the anisotropy in the attractive and repulsive interactions. The choice of these parameters is not straightforward and it would seem that those employed in some simulations are not strictly appropriate for mesogenic rodlike molecules. Here we report a detailed computer simulation study of Gay–Berne particles interacting via a potential parametrized to reflect the anisotropic forces based on a fit to a realistic mesogenic molecule. The behavior of the phases and the transitions between them have been investigated for a system of 2000 particles using isothermal–isobaric Monte Carlo simulations. At low pressures, this Gay–Berne mesogen exhibits isotropic, smectic A and smectic B phases but, as the pressure is increased, so a nematic phase is added to the sequence. The nature of the phase transitions and the phase diagram are compared where possible with those of real mesogens. The structures of the four phases have been investigated in detail for a larger system of 16 000 particles using canonical molecular dynamics simulations at state points taken from the phase diagram determined from the Monte Carlo simulations. A wide range of singlet and pair distribution functions were evaluated together with orientational correlation coefficients and, for the smectic phases, a bond orientation correlation function. The results for these properties were used to identify the phases, to consider their structure at a quantitative level and, where possible, to make contact with experimental studies and the predictions of theories of liquid crystals. It would appear that with this parametrization, the Gay–Berne potential provides a powerful tool with which to understand the behavior of real liquid crystals and to test the predictions of theory.Keywords
This publication has 38 references indexed in Scilit:
- A rigid core-flexible chain model for mesogenic molecules in molecular dynamics simulations of liquid crystalsThe Journal of Chemical Physics, 1996
- Monte Carlo simulations on mesophase formation using dipolar Gay–Berne modelLiquid Crystals, 1996
- Computer-simulation studies of anisotropic systems. Part XXIV.—Constant-pressure investigations of the smectic B phase of the Gay–Berne mesogenJournal of the Chemical Society, Faraday Transactions, 1995
- Liquid crystal phase diagram of the Gay-Berne fluidMolecular Physics, 1991
- Computer simulation studies of anisotropic systems. XIX. Mesophases formed by the Gay-Berne model mesogenLiquid Crystals, 1990
- Computer simulation studies of anisotropic systemsMolecular Physics, 1987
- Modification of the overlap potential to mimic a linear site–site potentialThe Journal of Chemical Physics, 1981
- Nematic-Liquid-Crystal Order—A Monte Carlo CalculationPhysical Review A, 1972
- Gaussian Model Potentials for Molecular InteractionsThe Journal of Chemical Physics, 1972
- The second virial coefficient of a gas of non-spherical moleculesProceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1948