Large-scale accurate structure calculations for open-shell atoms and ions

Recent progress and developments in the field of atomic structure theory are reviewed. To obtain reliable results also for open-shell atoms and ions, large-scale computations are required and are typically carried out in the framework of the configuration interaction or multiconfiguration Hartree-Dirac-Fock methods which help include relativistic. correlation and rearrangement effects of the electron density consistently. The success of such computations, however. depends not only on the shell structure of the atoms but to a large extent. also on the capabilities and the flexible use of the tools which are available. With the R-AT1P package we now provide a program environment which supports, apart from systematic investigations on open s- and p-shell configurations, also case studies on open d- or f-shell elements which will be put special emphasize on in this contribution. But, although. I will need to refer for most details to the original literature, the future and prospects of large-scale atomic calculations for complex shell structures will be summarized below.