title: Simple model for biaxial smectic-A liquid-crystal phases.
abstract: We have generalized the McMillan theory of liquid crystalline smectic order in uniaxial particle fluids to biaxial particles. Upon varying the control parameter, a uniaxial nematic phase may: (i) order biaxially first, then smectically; (ii) order smectically first, then biaxially; and (iii) simultaneously order biaxially and smectically. We investigate, in the limit of complete orientational order of the molecular major axes, which of these scenarios are realized for a simple model of particles with the symmetry of rectangular parallelepipeds. We also present a generic variational derivation of the theory based on the identification of the dominant order parameters for the most ordered phase.
authors.affiliation: Faculdade de Engenharia, Universidade Católica Portuguesa, Estrada de Talaíde, P-2635-631 Rio de Mouro, Portugal.
authors.forename: P I C
authors.initials: PI
authors.lastname: Teixeira
authors.forename: M A
authors.initials: MA
authors.lastname: Osipov
authors.forename: G R
authors.initials: GR
authors.lastname: Luckhurst