COMPUTER-SIMULATIONS USING A LONGITUDINAL QUADRUPOLAR GAY-BERNE MODEL- EFFECT OF THE QUADRUPOLE MAGNITUDE ON THE FORMATION OF THE SMECTIC PHASE

Systems of Gay-Berne particles with longitudinal linear quadrupoles ar e studied by molecular dynamics simulations. The effect of the magnitu de of the quadrupole on the smectic phase is investigated. It is found that the quadrupole destabilises the formation of the smectic phase w hich disappears altogether with high-magnitude quadrupoles. As the mag nitude of the quadrupole is reduced a variety of smectic phases are fo rmed, including smectic A, smectic C and smectic B, with the eventual formation of a crystal. The maximum magnitude of the tilt observed is 17.2 degrees, comparable with experimentally observed magnitudes. (C) 1998 Published by Elsevier Science B.V. All rights reserved.