  We present methodologies for calculating the direct correlation function,
c(1,2), the cavity function, y(1,2), and the bridge function, b(1,2), for
molecular liquids, from Monte Carlo simulations. As an example we present
results for the isotropic hard spheroid fluid with elongation e=3. The
simulation data are compared with the results from integral equation theory. In
particular, we solve the Percus-Yevick and Hypernetted Chain equations. In
addition, we calculate the first two terms in the virial expansion of the
bridge function and incorporate this into the closure. At low densities, the
bridge functions calculated by theory and from simulation are in good
agreement, lending support to the correctness of our numerical procedures. At
higher densities, the hypernetted chain results are brought into closer
agreement with simulation by incorporating the approximate bridge function, but
significant discrepancies remain.
