During mechanism generation, proposed adsorbates will descend down the decision tree to search for a match in the database. If no exact match is found, the closest structure is used in conjunction with the properties of the adsorbate's gas-phase counterpart. More specifically, a precompiled adsorption correction of the closest structure (or a branch average depending on the new adsorbate's location in the tree) is used to estimate the thermodynamic properties of the new adsorbate by adding the properties to the gas-phase thermochemistry.