as compared to smaller ones. (Note that this is not an artifact of the finite number of excited states because it is the higher-energy peak that is more intense in larger clusters.) Peak positions and relative intensities appear to converge at (TiO 2 ) 7 . Figure examines basis-set effects for CAM-B3LYP/ CIS calculations using the largest of these clusters, (TiO 2 ) 10 . The double-ζ basis sets def2-SV(P) and def2-SVPD result in a small (∼ 2 eV) shift as compared to the def2-TZVPD basis set for which the method was parameterized, but the overall spectral shape is nearly identical. The def2-TZVP basis set affords a spectrum that is nearly indistinguishable from the one obtained using def2-TZVPD. This is not unique to DFT/CIS and we have previously documented that core-level spectra computed using TD-DFT/double-ζ calculations are quite similar to results obtained in larger basis sets, including those that contain core-valence polarization functions 107 or uncontracted primitive Gaussians 80 that are intended to add variational flexibility in the description of the core hole. Use of def2-SV(P) speeds up the CAM-B3LYP/CIS calculation by ∼ 23× as compared to def2-TZVPD, suggesting that neither specialized basis sets nor basis sets of triple-ζ quality are required for XANES calculations using DFT/CIS or TD-DFT.