  Multi-group method is an accepted technique for approximately solving the
equation of radiative transfer. In this paper, group averaged transfer
scattering cross sections, required for solving the equation of radiative
transfer in a multi-group approach, are presented. Compton scattering is
approximately described by the Compton cross section for free electrons at
rest. In the low photon energy limit analytical results for scattering
coefficients have been derived.
