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