The above link gives access to the X-ray background synthesis code presented by Akylas et al. (2012, A&A,546, 98). The code returns the integrated XRB spectrum in the energy range 1-200 keV and the cumulative logN-logS of AGN in user defined energy bands, redshift, luminosity and NH intervals.
The calculations use the Ueda et al. (2003) 2-10 keV X-ray luminosity function and hydrogen column density distribution as well as the template AGN spectra produced by the Monte-Carlo simulations described by Brigthman & Nandra (2011, MNRAS, 412, 1206).
Input parameters to the code include the spectral characteristics of the AGN:
(i) the mean spectral index Gamma of the intrinsic AGN power-law spectrum,
(ii) the high energy cutoff Ec of the intrinsic AGN spectrum,
(iii) the fraction of the direct AGN radiation in the rest-frame 2-10 keV band that is reflected into the line of sight.
The user also has control on the fraction of Compton Thick AGN that are added to the Compton Thin X-ray luminosity function of Ueda et al. (2003), in the user specified column density interval.