Like ∆SCF, however, the eigenvalue-based methods can be expected to depend sensitively on the choice of exchange-correlation (XC) functional. The present work systematically investigates different core-hole constraining approaches using XC functionals on various rungs of Jacob's ladder. It follows a similar investigation of fractional-electron methods for computing core-level electron binding energies, intended for computational xray photoelectron spectroscopy (XPS). In that previous work, we demonstrated that an empirically-shifted version of STM with a single fitting parameter affords more accurate K-shell electron binding energies than even the best ab initio methods, including GW -type methods. A similar empirical shifting procedure is introduced here for core-level excitation energies, and is shown to perform quite well.