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X-ray absorption spectroscopy (XAS) at the L3 edge of mixed-valence Ce and Yb compounds is a powerful tool for measuring the valence of Ce and Yb ions, but in order to obtain the valence in the ground state it is necessary to analyze the effect of the final-state interaction on XAS profiles, which gives rise to some correction for the XAS-derived valence. We theoretically compare the difference in the final-state interaction for Ce and Yb compounds whose ground states are in the electron–hole symmetry. It is found that the correction for the valence by the final-state interaction is much larger for Ce than for Yb, even if the valences in the ground state are the same. In order to discuss the mechanism of this observation, we define two different final-state interactions: (i) the final-state hybridization between the 4f0 and 4f1 configurations and (ii) that between the 4f1 and 4f2 configurations. Among (i) and (ii) of Ce and Yb compounds, (ii) of Ce compounds is much larger than other interactions, because the core hole potential is attractive for the Ce 4f electron but repulsive for the Yb 4f hole.
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