Nonrelativistic limit of Dirac-Fock codes: the role of Brillouin configurations.

@article{Indelicato2005NonrelativisticLO,
  title={Nonrelativistic limit of Dirac-Fock codes: the role of Brillouin configurations.},
  author={P. J. Indelicato and Eva Lindroth and J. P. Desclaux},
  journal={Physical review letters},
  year={2005},
  volume={94 1},
  pages={013002}
}
We solve a long standing problem with relativistic calculations done with the widely used multiconfiguration Dirac-Fock method. We show, using relativistic many-body perturbation theory (RMBPT), how, even for relatively high-Z, relaxation or correlation causes the nonrelativistic limit of states of different total angular momentum but identical orbital angular momentum to have different energies. We show that only large scale calculations that include all single excitations, even those obeying… CONTINUE READING