Finally, we provide comments on the proper use of diffuse functions. Ref. 1 suggests these should be used only when warranted, leaving open the question of when that might be. Diffuse functions are important for converging noncovalent interaction energies, and they can be important for thermochemistry, barrier heights, and isomerization energies. They are often needed for excitation energies computed using timedependent DFT, and the 6-311+G(2df,p) basis set is found to afford converged results in that capacity. For ground-state thermochemistry, we find that the minimally-augmented def2-ma-TZVP basis set, which is a proper subset of def2-TZVPD, performs just as well as 6-311+G(2df,p) but is less expensive.