reference values, where the line colors refer to the respective isomers. These supermolecular relative energies span a range of roughly 45 kJ/mol. The values calculated with the different MBEs are shown by the colored symbols. In the case of perfect agreement, these symbols would be on top of the horizontal line of the same color. The mean and maximum errors in both the total interaction energies and the relative interaction energies across all ten structural isomers are listed in Table . For the relative interaction energies, the lowest-energy isomer is not included because its error is zero by definition.