Failure of multiconfiguration Dirac-Fock wave functions in the nonrelativistic limit

Abstract
Multiconfiguration Dirac-Fock (MCDF) wave functions for a specific J quantum number may not reduce to the appropriate nonrelativistic limit for the L and S quantum numbers. Transition probabilities calculated from such MCDF wave functions for spin-forbidden transitions are unreliable. Remedies for this problem are discussed, including the advantages of using nonorthogonal radial orbitals. It is also shown that transition probabilities for weak transitions are sensitive to the way the Breit interaction is introduced.