  A spherocylinder-like molecule with a Lennard-Jones type interaction is
proposed as a model of smectic-A (Sm-A) liquid crystals, which can form a
free-standing film. By means of Gibbs ensemble simulations, the isotropic,
nematic, and Sm-A phases of the model fluid are found to coexist with a vapor
phase; and the coexistence conditions of the liquid crystal phases with the
vapor phase are determined. For a set of the interaction-parameters of the
model molecule, the Sm-A free-standing film is produced below the bulk
isotropic--Sm-A phase transition temperature by using Monte Carlo simulations.
The film tension of the Sm-A free-standing film is calculated and its
dependencies on the temperature and on the number of molecules are discussed.
