Electron removal energies from density functional computations

We present a simple method for estimating electron removal energies from ground-state density functional computations. We discuss the relation of our method with previous schemes, like the self-interaction correction, the Slater transition state method, and a semi-empirical scheme. The comparison of our results with experimental data for atoms and molecules shows that the proposed method corrects most of the error present in the single electron eigenvalues of density functional theory.