LAUSR

We develop a simple semiempirical model that correlates the Auger parameter to the ground state valence charge of the core‐ionized atom with closed shell electron configuration. Until now, the Auger parameter was employed to separate initial and final state effects that influence the core electron binding energy. The model is applied to Cu(I) and Cu (II) compounds with the Auger parameter defined as α' = EbFL (2p3/2) + EkFL (L3M45M45;1G). The Auger parameter shift for Cu(I) ion in CuI, CuBr, CuFeS2, Cu2S, and Cu2O compounds—with respect to the copper free atom—increases with the electronic polarizability of the nearest‐neighbour ligands suggesting a nonlocal screening mechanism. This relaxation process is interpreted as due to an electron transfer from the nearest‐neighbour ligands toward the spatially extended 4sp valence orbitals of the core‐ionized Cu(I) ion. In agreement with our model, a linear relationship is found between the Auger parameter shift and the ground state Bader valence charge obtained by density functional theory calculations.