Blaylock et al. developed a similar approach, where they also used an expression similar to Eq. ( ). Instead of gas-phase reference species, they used adsorbates as reference species for the atomic reference basis set. They determined ∆ f H of *H, *O, and *CO on Ni(111) from experimentally measured adsorption enthalpies . In combination with the known ∆ f H of the gas-phase precursors (H 2 , O 2 , CO) from a global thermochemical network like ATcT, we can derive ∆ f H of the reference adsorbates using the thermochemical cycle in Fig. . ∆ f H of the adsorbed reference species are referenced to the global thermochemical network, and all other adsorbates are then referenced to these reference species according to The method to determine ∆ f H P* is straightforward and similar to the method in Section 4.3.2. ∆ f H P* is calculated from the reaction enthalpy to form the target from the references from DFT and the sum of the ∆ f H of the references.