The performance of commonly used correlation and exchange-correlation functionals has been studied for highly charged atomic ions. Calculated energies have been compared with exact nonrelativistic energies of atomic species with 2–18 electrons for nuclei from $Z=2\mathrm{}$ (He) to $Z=26\mathrm{}$ (Ni). It is found that all density functionals considered here reveal problems in the description of correlation effects as a function of nuclear charge Z.

• Received 14 May 1998

DOI:https://doi.org/10.1103/PhysRevA.58.1902