The results obtained in Parts 1 and 2 show very clearly that the use of DZVP-SR basis sets results in systematically more negative adsorption energies compared to TZVP-MOLOPT basis sets. The differences among results obtained with basis sets of different size vary considerably, depending on the dc-XC functional used and the adsorbate. Reassuringly, the comparison of adsorption energies obtained with TZVP-MOLOPT basis sets for cluster models to CBS-extrapolated values (TZV2P-GTH/QZV3P-GTH) showed only modest quantitative differences (𝑀𝑆𝐸 on the order of -3 to -5 kJ mol -1 , corresponding to relative errors of 3.5 to 6%, see bottom of Table .1). This indicates that TZVP-MOLOPT basis sets may constitute a good balance between accuracy and computational cost, especially for periodic systems.