So far this discussion has been confined to error statistics with respect to the DFT/CBS limit but it is important not to lose sight of accuracy with respect to benchmark interaction energies. Table lists error statistics with respect to CCSD(T)/CBS benchmarks, for the functionals and basis sets in Table . With the exception of the notably less-accurate M06-L functional, the errors fall within < 0.6 kcal/mol of the benchmarks when CP correction is employed, but exceed 2 kcal/mol in some double-ζ basis sets when the CP correction is omitted. With CP correction and diffuse functions (i.e., excluding the basis sets 6-31G* and def2-SVP), the double-ζ errors are 0.4 kcal/mol. CP correction is thus crucial not only for achieving the CBS limit but also for improving the accuracy of small-basis interaction energy calculations.