Brief Reports are accounts of completed research which, while meeting the usual Physical Review standards of scientific quality, do not warrant regular articles. A Brief Report may be no longer than four printed pages and must be accompanied by an abstract. The same publication schedule as for regular articles is followed, and page proofs are sent to authors.The high-binding-energy structure in the Eu 3d core-level x-ray photoelectron spectra of divalent Eu compounds, which has been ascribed as the "shakeup" satellite, is shown to be due to the multiplet structure of 3d4f i (bar denotes a hole) final-state configuration. Hence, the apparent inconsistency between this so-called high-energy probe and low-energy probes for the valence of these Eu compounds is resolved.Rare-earth metals and their compounds have been the subject of extensive study because of the valence Auctuation phenomena' and heavy fermion properties, which originate from the interaction between highly correlated 4f electrons and delocalized conduction electrons. Corelevel x-ray photoelectron spectroscopy (XPS) has been very valuable in studying electronic structures of these compounds. Core-level spectra can be usually understood by the following Anderson impurity Hamiltonian including the Coulomb interaction between the core hole and 4f electrons: ' XH = g f Ftp, +"tp"de+[a& -U&, (1 n, )]q&+ -pt v= 1 + f [V(e)tp" tp"+ V(e)*tp, +, tp, ]dE + UJJ g~n~n E+~n P)V where e describes the energy of the conduction-band state, e& is the energy of the 4f level, and E, describes the energy of a core level. The 4f level has N&-fold degeneracy, whose quantum numbers are denoted by p, v. The hopping between the 4f level and the conduction state is described by V(e) and the Coulomb interaction between 4f electrons is given by UI&, where in the simple model multiplet effects are neglected. U&, is the Coulomb interaction between a core hole and an f electron. Thus while the~f")and~f" + ' ) states are nearly degenerate in energy in the initial state, they have an energy separation of U&, in the final state of photoemission, because the energy of the~f ") state is pulled down by the amount n U&, (n is the number of f electrons) by the core hole created in photoionization.This gives rise to the satellite structure in the deep core-level XPS spectra, whose intensity depends on the strength of V(e) and the energy position of e&. Therefore, by analyzing deep core-level XPS spectra, we can get information of the valence electronic structure. For this purpose 3d core-level spectra usually used because 4d core-level XPS shows very complicated multiplet structures due to the strong interaction between the 4d hole and unfilled 4f shell (they have the same principle quantum number n =4). Many Ce compounds and several Yb compounds have been studied by the core-level XPS technique, and they are shown to be consistent with physical properties measured by so-called low-energy probe techniques such as Mossbauer isomer shift and the magnetic susceptibility. ' However, for some Eu co...