  We have used the density-functional theory to locate the freezing transitions
and calculate the values of freezing parameters for a system of long elongated
molecules which interact via the Gay-Berne pair potential. The pair correlation
functions of isotropic phase which enter in the theory as input informations
are found from the Percus-Yevick integral equation theory. At low temperatures
the fluid freezes directly into the smectic A phase on increasing the density.
The nematic phase is found to stabilize in between the isotropic and smectic A
phases only at high temperatures and high densities. These features of the
phase diagram are in good agreement with the computer simulation results.
