It is clear from these data that there is no strong correlation between molecule size and the number of gradient evaluations required to reach convergence. This is perhaps not surprising, considering the small range of molecule sizes included in this study, though it is not at all a guaranteed property. For optimizations in a basis of redundant internal coordinates, it is crucial to use a trust region condition that scales appropriately with the system size, rather than the dimensionality of the basis. If one were to use a 2-norm based trust region condition, the apparent magnitude of any given displacement will increase if additional redundant coordinates are added to the coordinate system. It is for this reason that we choose to use the infinity-norm for the trust region condition, as displacements are limited by only the largest-changing component, and thus the addition of more redundant coordinates will generally not change the displacement magnitude.