First, due to a lack of training data, the GAVs do not include halogen-specific ring corrections for ring sizes greater than 4 atoms. The mean absolute deviation for cyclic species with ring sizes greater than 4 was 7.42 kcal/mol compared to 6.09 kcal/mol for three and four member rings. Second, the long-distance corrections in RMG are not applied for neighboring atoms if one atom is in a ring and the other atom is outside the ring. A missing long-distance interaction between halogens on atoms in and out of a ring would lead to systematic underprediciton of ∆ f H • 298K for these types of molecules, which may be reflected in the negative mean signed deviation for cyclic compounds in the test set. Third, because RMG was used to build the test set and RMG prefers to incorporate low energy molecules in its models (endothermic reactions are typically slower), there is a bias for underestimated (i.e. lower energy) molecules to be selected for the test set. In other words, it is more likely for molecules that the GAVs underestimated (negative MSD) to end up in the test set than overestimated or correctly estimated molecules. Although the current GAV estimates do not perform as well for cyclic halocarbons as noncyclic ones, the estimates are good enough to be helpful in the automated construction of microkinetic models, and are a vast improvement on RMG's estimates before this work.