Hartree-Fock calculations are used to investigate screening effects on the values of ${\left|\psi \mathrm{}\right(0\left)\right|}^2$ for heavy atoms. It is shown that such calculations represent reasonably well the actual screening behavior derived from observed isotope (and isomer) shifts. In addition to the already known importance of $5p$ and $5d$ electron screening effects, it is found, in the case of the actinides, that $5f$ screening effects are also important.

• Received 3 June 1968

DOI:https://doi.org/10.1103/PhysRev.176.58