It is possible to combine the ∆ f H of the adsorbates with the known global thermochemical network of gas-phase reactions to achieve reaction enthalpies of gas-phase reactions that are in exact agreement with the known ∆ f H from the ATcT. The approach to reference the DFT energies to the ATcT is similar to the approach described in Section 4.2.2. Assuming an atomic reference basis set with CH 4 , H 2 O, H 2 , and Pt(111), we can again create a reaction to form the target from the references.