For CAM-B3LYP/CIS, errors are comparable in magnitude and have the same sign as errors obtained using TD-SRC1-r2, although both methods exhibit larger errors as compared to what we observed for second-row elements (Table ). Using B3LYP/CIS, the error is of opposite sign to that of TD-B3LYP and is significantly Fig. : Oxygen K-edge spectra computed using CAM-B3LYP/CIS for TiO2 clusters with differing numbers of formula units. All spectra were computed using 1000 transition energies broadened using a Gaussian width of 0.3 eV. Each spectrum is scaled so that its most intense feature has unit intensity so that the intensity scale can be compared across all five spectra. larger than that of CAM-B3LYP/CIS, illustrating why that method needed to be reparameterized for heavier elements. As discussed in Section II B, the formulation of CAM-B3LYP/CIS used TD-SRC1 as reference data to parameterize ∆ε, and this is apparent in the data as the two methods exhibit comparable errors that follow similar trends.