Monte Carlo simulation of liquid-crystal alignment and chiral symmetry-breaking

We carry out Monte Carlo simulations to investigate the effect of molecular shape on liquid-crystal order. In our approach, each model mesogen consist s of several soft spheres bonded rigidly together. The arrangement of the s pheres may be straight (to represent uniaxial molecules), Z-shaped (for bia xial molecules), or banana-shaped (for bent-core molecules). Using this app roach, we investigate the alignment of the nematic phase by substrates deco rated with parallel ridges. We compare results for wide and narrow ridge sp acing and examine local order near the substrates, and show that our result s are consistent with the predictions of Landau theory. We also investigate chiral symmetry-breaking in systems of bent-core molecules. We find a chir al crystalline phase as well as a nonchiral smectic-A phase, but not a chir al smectic-C phase. (C) 2001 American Institute of Physics.