The experimental spectra for the empty MOF and upon CO and CO2 adsorption are shown in Figure (upper panel) together with scattering function computed using eq. 1 panel). For the bare material the pyrazines are considered perpendicular in agreement with previous calculations and experimental findings. The scattering function upon CO adsorption in Figure is computed by adopting the configuration described in the previous section with 2 molecules per f.u. and pyrazines in a parallel orientation. For CO2, we consider 1.5 molecules per f.u. and a parallel orientation of the pyrazines.