DFT calculations were carried out using the CP2K code, version 7.1, installed on the HLRN-IV facilities of the North-German Supercomputing Alliance. All calculations used the rev-vdW-DF2 functional, which was found to perform well in previous studies of guest-free zeolite structures and of adsorption complexes of different contaminants in all-silica zeolites. Goedeker-Teter-Hutter pseudopotentials devised by Krack were employed to represent the core electrons. The first Brillouin zone was sampled at the Γ-point, only. Prior to the calculation of adsorption energies, the structures of the adsorption complexes, of guest-free zeolites, and of isolated CBZ were optimized, in each case optimizing all atomic coordinates, but fixing zeolite cell parameters to experimental values (Supporting Information, Table ).