Failure of single-configuration Dirac-Fock wave functions in the nonrelativistic limit

We have found earlier that a certain type of multiconfiguration Dirac-Fock wave function may not have the correct nonrelativistic limit in the spin quantum number, and hence may result in large errors in the transition probabilities for spin-forbidden, weak transitions. In this article, we report that the failure to have the correct nonrelativistic limit can also occur in a certain type of single-configuration Dirac-Fock wave functions. Examples of such a case, along with an effective remedy, are illustrated using the spin-forbidden transitions, 2p43s 4P →2p52P, in F and Ne+