The attractive ALMO-EDA energy components are shown in detail in Figure for two representative cases, C and CH at the hollow site of the various metals. Here the electrostatic interaction clearly contributes the most to the total adsorption energy. As shown in Tables S1-S5, this is generally true for the hollow and bridge sites but not for the ontop site, where the charge-transfer contribution dominates. This is expected as an adsorbate at the ontop site is the furthest from the surface, leading to weaker electrostatic interaction due to its 1/r n dependence. In the context of the energetics of the frozen state, the electrostatic attraction is offset entirely by the positive Pauli repulsion energies. Thus, the frozen state, with a net positive interaction energy, does not provide the driving force for the adsorption. The polarization and charge transfer interactions are essential to achieve an overall favorable binding.