The degeneracy effects in the isoelectronic series of the second-row atoms are analyzed. New values are estimated for the correlation energies. The correlation energy diagram exhibits a remarkable similarity with the corresponding one for first-row atoms and ions. We have added a new table of data which summarizes the results for the first- and second-row correlation energies. These data make use of previously unpublished computations on the relativistic effects.
Veillard et al. (Sun,) studied this question.