The def2-TZVP basis set is convenient, not least because it is defined for the entire periodic table, although G3Large has been extended to 3d transition metals. In any case, for main-group thermochemistry there are comparable and even superior Pople-style alternatives. To choose between these options, computational cost may be part of the consideration. Figure presents timing data for a selection of basis sets using a diazacrown ether naphthalimide (C 41 H 50 O 6 N 4 ) as a test case. (Timing data for additional basis sets can be found in Fig. .) For all three functionals considered here, the 6-311G(2d,p) basis set is 1.7× faster than def2-TZVP despite containing 99 more basis functions. This economy is partly the result of the compound sp shells used in Pople basis sets; see Fig. . These reduce the variational flexibility, as noted long ago and discussed at length in Ref. 1, nevertheless the accuracy documented herein speaks for itself.