Many-electron correlation effects on anomalous scattering factors

The effect of many-electron correlations on anomalous scattering factors in Rayleigh scattering is studied, in the case of the Ar atom, using dispersion relations and the relativistic random-phase approximation (RRPA). The correlation effect changes the Ar 3s-subshell photoionization cross sections significantly compared with the corresponding independent-particle approximation calculations; thereby the anomalous scattering factors of Rayleigh scattering from this subshell also experience marked structural changes. But the Ar 3p subshells dominate the coherent total-atom scattering amplitude so that subshell structural changes in the Ar 3s subshell due to many-electron correlation effects are not seen in the total-atom scattering cross section or the total-atom anomalous scattering factors, which are the physical observables in Rayleigh-scattering experiments. One anticipates this outcome generally for closed-shell atoms, while in the case of open shells one can anticipate a greater importance for the many-electron-correlation effects