  We present a full set of model atmosphere equations for the accretion disk
around a supermassive black hole irradiated by hard X-ray lamp of power-law
spectral distribution. Model equations allow for multiple Compton scattering of
radiation on free electrons, and for large relative photon-electron energy
exchange at the time of scattering. We present spectra in specific intensities
integrated over the disk surface. Theoretical outgoing intensity spectra show
soft X-ray excess below 1 keV, and distinct K_alpha and K_beta fluorescent
lines of iron. We demonstrate the existence of the Compton Shoulder and claim
that it can contribute to the asymmetry and equivalent widths of some observed
Fe K_alpha lines in AGN. Our models exhibit the effect of limb-brightening in
reflected X-rays.
