Lightly ionized medium to high-Z atoms have been little studied theoretically, because they require the simultaneous inclusion of relativity and correlation. For the latter, the presence of open d and/or f subshell electrons makes obtaining accurate computational results quite challenging. These species, which constitute over half the periodic table, are technologically important in catalysis, advanced lighting sources, atomic clocks, nuclear waste, semi-conductor defects, rare-earth magnets, high temperature superconductors, hydrogen energy storage, plasma fusion devices, astrophysics, etc. For localized properties, at least, what we learn about atomic basis sets (one- and N-electron) can be fruitfully transferred to solid and molecular studies. The negative ions are particularly challenging to both the theorist and experimenter. Without correlation, most systems are unbound, and adding an electron significantly disturbs the system, requiring careful treatment of at least the outer electrons (valence and shallow core). The current project completes the extension of the Relativistic Configuration Interaction Methodology to continuum properties of anions, such as resonances (energies and widths) and photoionization cross sections. The second focus in this proposal is to extend existing bound state methodology, so that the difficulties in treating middle row lanthanides and actinides will be reduced.
