Correlation Energy in Atomic Systems. III. Configurations with 3<i>d</i> and 4<i>s</i> Electrons

Abstract

The correlation energy for systems containing 3d and 4s electrons has been examined making use of recently obtained Hartree-Fock energies for the elements from K to Zn. In addition to the expected pair correlation between 3d electrons, a large extrashell correlation has been found. These results make it desirable to re-examine the simple correlation model previously put forward. The relativistic correction for the elements in consideration has been discussed.