Computer simulation studies of anisotropic systems. XXVI. Monte Carlo investigations of a Gay–Berne discotic at constant pressure

The majority of molecules which form liquid crystals are elongated in shape. However, disk shaped molecules have also been shown to exhibit liquid crystalline phases. In this paper we report a series of constant pressure Monte Carlo simulations of model discotic molecules. We have used the Gay–Berne potential, which is in essence an anisotropic version of a shifted Lennard‐Jones potential, to model the interactions between the disks. Initially we studied a system of 512 molecules over a range of pressures to determine the mesophases formed and to construct the phase diagram. The system was found to exhibit isotropic, nematic, and columnar phases. We have also studied a larger system of 2000 molecules at a single pressure to calculate more accurately the distribution functions used to describe the translational and orientational order within the various phases.

[1]  C. M. Care,et al.  Computer modelling of discotic liquid crystals , 1994 .

[2]  G. R. Luckhurst,et al.  Computer simulation studies of anisotropic systems: XXIII. The Gay-Berne discogen† Presented at the European Liquid Crystal Conference, Flims, Switzerland, 8–12 March 1993. , 1994 .

[3]  C. M. Care,et al.  Molecular dynamics simulations of discotic liquid crystals using a hybrid Gay–Berne Luckhurst–Romano potential , 1994 .

[4]  G. R. Luckhurst,et al.  Computer simulation studies of anisotropic systems: XXI. Parametrization of the Gay-Berne potential for model mesogens , 1993 .

[5]  G. R. Luckhurst,et al.  Computer simulation studies of anisotropic systems. XX: On the validity of the Maier-Saupe approximations for the Gay-Berne nematogen , 1992 .

[6]  D. Frenkel,et al.  Phase behavior of disklike hard-core mesogens. , 1992, Physical review. A, Atomic, molecular, and optical physics.

[7]  Luis F. Rull,et al.  Liquid crystal phase diagram of the Gay-Berne fluid , 1991 .

[8]  L. F. Rull,et al.  LOCATION OF THE ISOTROPIC-NEMATIC TRANSITION IN THE GAY-BERNE MODEL , 1991 .

[9]  L. F. Rull,et al.  LIQUID-VAPOUR COEXISTENCE OF THE GAY-BERNE FLUID BY GIBBS-ENSEMBLE SIMULATION , 1990 .

[10]  G. R. Luckhurst,et al.  Computer simulation studies of anisotropic systems. XIX. Mesophases formed by the Gay-Berne model mesogen , 1990 .

[11]  Frenkel,et al.  Phase diagram of a system of hard spherocylinders by computer simulation. , 1990, Physical review. A, Atomic, molecular, and optical physics.

[12]  Daan Frenkel,et al.  Structure of hard-core liquid crystals , 1988 .

[13]  D. Frenkel,et al.  Thermodynamic stability of a smectic phase in a system of hard rods , 1988, Nature.

[14]  J. Banavar,et al.  Computer Simulation of Liquids , 1988 .

[15]  G. R. Luckhurst,et al.  Computer simulation studies of anisotropic systems: XVII. The Gay-Berne model nematogen , 1987 .

[16]  D. Frenkel.  Computer simulation of hard-core models for liquid crystals , 1987 .

[17]  R. Eppenga,et al.  Monte Carlo study of the isotropic and nematic phases of infinitely thin hard platelets , 1984 .

[18]  D. Frenkel,et al.  Phase diagram of a system of hard ellipsoids , 1984 .

[19]  B. Berne.  Modification of the overlap potential to mimic a linear site-site potential , 1981 .

[20]  N. H. Tinh,et al.  On a “cholesteric” phase in disc-like mesogens , 1980 .

[21]  K. A. Suresh,et al.  Liquid crystals of disc-like molecules , 1977, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[22]  Bruce J. Berne,et al.  Computer simulation of anisotropic molecular fluids , 1976 .

[23]  Bruce J. Berne,et al.  Gaussian Model Potentials for Molecular Interactions , 1972 .

[24]  J. Wheeler,et al.  Critical Points in Multicomponent Systems , 1970 .

[25]  J. A. Barker,et al.  Structure of water; A Monte Carlo calculation , 1969 .

[26]  L. Verlet.  Computer "Experiments" on Classical Fluids. I. Thermodynamical Properties of Lennard-Jones Molecules , 1967 .

[27]  G. R. Luckhurst,et al.  Computer-simulation studies of anisotropic systems. Part XXIV.—Constant-pressure investigations of the smectic B phase of the Gay–Berne mesogen , 1995 .

[28]  Daan Frenkel,et al.  Hard convex body fluids , 1993 .

[29]  Andrew P. J. Emerson,et al.  Monte Carlo investigations of a Gay—Berne liquid crystal , 1993 .

[30]  S. Chandrasekhar.  Discotic liquid crystals. A brief review , 1993 .

[31]  J. Wendorff,et al.  Structural and dynamic properties of a new type of discotic nematic compounds , 1989 .

[32]  Daan Frenkel,et al.  Columnar ordering as an excluded volume effect , 1989 .

[33]  Keith E. Gubbins,et al.  Theory of molecular fluids , 1984 .

[34]  G. R. Luckhurst,et al.  The Molecular physics of liquid crystals , 1979 .