Improved RCI techniques for atomic 4fn excitation energies: application to Sm I 4f66s25DJ levels

We complete the development of a relativistic energy-dependent efficient method by which important pair-correlation effects associated with open subshells can be incorporated into the relativistic configuration interaction (RCI) methodology. We apply this to predict the positions of the 4f66s25DJ levels of Sm I. Relative to 5D1, we predict 5D0 lies at -1613 cm-1 and 5D4 at 6589 cm-1. For 5D2 and 5D3, we are 22 cm-1 and 123 cm-1 below the observed difference, respectively. We also calculate magnetic dipole transition rates among these levels and the ground-state 7FJ levels, which may be of interest to future parity nonconservation studies.