Several previous studies have explored modified Gaussian basis sets for use in XAS calculations. In some cases, standard Gaussian basis sets have been "uncontracted", meaning that each Gaussian primitive is used as an independent basis function, thus improving the variational flexibility of the core functions. A separate strategy is to use basis sets that include core-valence polarization functions, such as cc-pCVXZ. It has been suggested that these basis sets work well for core-level spectroscopy precisely because the additional polarization functions are uncontracted. In contrast to the behavior observed using correlated wave functions, our testing with LR-TDDFT reveals that uncontracting the basis sets modifies the nearedge excitation energies by < 0.1 eV and modifies spectra hardly at all, even at much higher excitation energies (Fig. ). These tests include the basis sets 6-31+G(d), 6-311(2+,2+)G(d,p), (aug-)cc-pVTZ, augcc-pCVTZ, and def2-TZVPD. A previous LR-TDDFT study also concluded that basis set effects are rather small for XAS calculations, 87 although these effects are somewhat more pronounced for x-ray emission, because the reference state for LR-TDDFT involves core ionization in that case. (Emission spectra are not considered in the present work.) A summary of basis set effects is presented in Table , demonstrating that the SRC functionals predict oxygen and carbon K-edge excitation energies within 0.1-0.2 eV of experiment for small organic molecules. Those deviations are of the same magnitude (or smaller) than relativistic corrections for second-row elements. All LR-TDDFT calculations reported below were performed using the CVS approximation. Excitation energies were broadened using a Lorentzian func-tion with a width of 0.7 eV, in order to be directly comparable to spectra obtained from TDKS simulations.