Estimation of the integral role of intershell correlations in heavy atoms

We have calculated partial contributions of different atomic subshells to the total dipole sum rule in the random phase approximation with exchange and found that they are essentially different from the numbers of electrons in respective subshells. This difference manifests the strength of the intershell interaction, due to which some partial contributions are much larger while the other are considerably smaller than the numbers of electrons in the respective shells. Particularly impressive is the growth of contribution of the outer among $f$ and $d$ subshells while all other are usually losers, the largest of which are the s-subshells. Concrete calculations done for Ar, Pd, Xe, and Ra atoms. Comparison with existing experimental data is uninformative since to obtain the absolute values of the cross sections one usually normalizes them, assuming that the dipole partial sum rule is valid with reasonable accuracy.