Liquid crystals exhibit orientation-dependent phases ranging from a disordered (isotropic) phase to a highly ordered crystalline phase. In between these extremes, increasing order can result in nematic and smectic phases. Typically, molecular simulation studies of liquid-crystal behavior use a nonspherical hard-body monomer. In this work, molecular simulation is used to study dimers of hard prolate ellipsoids. The results indicate that dimers of hard prolate ellipsoids exhibit a rich diversity of liquid-crystal behavior including smectic phases. In some cases, the dimer model may be a more realistic alternative to the conventional monomer model for liquid-crystal behavior. (C) 2001 American Institute of Physics.