Due to the infeasibility of periodic DLPNO-CCSD(T) calculations, these calculations were performed for two cluster models of ACA@MOR adsorption complexes studied in Part 2, as well as a cluster model of the ACA@FAU complex studied in Part 1. For ACA@MOR, Config1 and Config3 were chosen for the following reasons: First, the ACA molecules are displaced from the channel centre, interacting primarily with one side of the channel wall. Therefore, a relatively small cluster model should be able to capture the largest part of the host-guest interactions. In contrast, the ACA molecule in Config2 lies across the channel, interacting with both sides, so a much larger model would be required (Figure ). Second, although DFT calculations deliver very similar adsorption energies for both configurations, Config3 contains a HOH•••Ofw hydrogen bond, whereas Config1 does not. All cluster models were cut out from the structures optimised using the PBE-D3 functional and TZVP-MOLOPT (for MOR) or DZVP-SR (for FAU) basis sets. They are visualised in Figure .