First-principles correction scheme for linear-response time-dependent density functional theory calculations of core electronic states

Linear-response time-dependent density functional theory (LR-TDDFT) for core level spectroscopy using standard local functionals suffers from self-interaction error and a lack of orbital relaxation upon creation the hole. As result, LR-TDDFT calculated X-ray absorption near edge structure (XANES) spectra need to be shifted along energy axis match experimental data. We propose correction scheme based on many body perturbation calculate shift first principles. The ionization potential donor state is computed then substituted corresponding Kohn--Sham energy, thus emulating Koopmans' condition. Both are taken into account. method exploits localized nature states efficiency integrates seamlessly in our previous implementation LR-TDDFT, yielding corrected single calculation. benchmark molecules at K- L-edges as well binding energies report accuracies comparable higher order methods. also demonstrate applicability large extended systems discuss efficient approximations.