For adsorption on the interface (ii) site, the changes are more subtle. In this case, the CO adsorption energy follows the trend in the CO binding energy, while changes in the other two contributions, from restructuring and changes in the interface energy, largely cancel out. This change in CO adsorption energy is most pronounced when going from the 2VO to the 3VO system, similar to the increase in CO binding energy at this point. Similar to our observation for individual vacancies, the differences between CO binding energy and CO adsorption energy are bigger for adsorption on the interface (ii) site (Table ) than for adsorption on the interface (i) site (Table ), indicating that also in this case the lower CO adsorption energies on the interface (ii) site are mainly due to larger (positive) contributions from the COad induced deformation energies and differences in the interface energies.