Semiempirical Sternheimer shielding factors for the atomic 4f and 5d shells

In a recent Physical Review Letter, workers at Los Alamos reported new electric-quadrupole moment values for selected nuclei through study of hfs in the X-ray spectra of muonic atoms. On combining these true moment values with the apparent values previously deduced for the same nuclei from many-electron hfs studies, the authors evaluated Sternheimer shielding factors for several electron shells in various atoms. They were struck by the unreasonably large scatter in the resulting shielding factors. After some study, the authors concluded that the scatter arose from (1) questionable assumptions and procedures used earlier in analyzing the many-electron hfs, and (2) the diversity of methods used in evaluating quadrupole radial hfs integrals. Limiting themselves to the atomic 4f and 5d shells, they made a study of all atoms for which (a) a true quadrupole moment value (i.e. one determined either by muonic hfs or Coulomb excitation) was known and (b) the many-electron hfs had been studied