Oscillator strengths for the eigenvalue-based methods can be implemented based on eq 2. Figure shows XAS spectra computed in this way (and compared to experiment), for both the shifted and unshifted XTPM proce-dure. Empirical shifting corrects the peak positions into good agreement with experiment, for both molecules, whereas the original XTPM procedure overestimates the transition energies. (Note that none of the thymine or oxazole transitions are in the data set used to obtain the shift parameters.) This suggests that shifted XTPM might be a useful approach for large systems where even TD-DFT might be inconvenient.