  We present a radiative transfer model which computes the spectral energy
distribution of a passive, irradiated, circumstellar disk, assuming the grains
are in radiative equilibrium. Dependence on radial density profile, grain
temperature estimation, and optical depth profiles on the output SED are
discussed. The bist fit model for HR4796A has a minimum and maximum spherical
grain size of 2.2 and 1000 \mu$m respectively, a size distribution slightly
steeper than the "classical" -3.5 MRN power law, grains composed of silicates,
trolite, ice, and organics and a peak radial density of 1.0 x 10^-17 g cm^-2 at
70 AU, yielding a disk mass of roughly 2 M_{oplus}$.
