The international collaboration on Computational Atomic Structure
To meet the demands for atomic data the Computational Atomic Structure (CompAS) group has been formed. The group is involved in developing state of the art computer codes for atomic calculations in the non-relativistic scheme with relativistic corrections in the Breit-Pauli approximation ATSP2K  as well as in the fully relativistic scheme GRASP2K . The codes rely on multiconfiguration methods and the wave function for an atomic state is expanded in configuration state functions (CSFs).
Moreover, the RATIP  program supports the calculation of atomic properties for open-shell atoms with one electron in the continuum, including transition probabilities, Auger parameters as well as a variety of excitation, ionization and recombination amplitudes and cross sections.
In addition to the code development itself, the group includes members with expertise in the methods and is constantly developing computational techniques for the evaluation of atomic properties of the highest quality.
Some of the group's research are highlighted in this "Lab Talk" article in Journal of Physics B.
1. C. Froese Fischer, G. Tachiev, G. Gaigalas and M. Godefroid, Comput. Phys. Commun., 176 559 (2007).
2. P. Jönsson, G. Gaigalas, J. Bieron, C, Froese Fischer and I.P. Grant, Comput. Phys. Commun., 184 2197 (2013).
3. S. Fritzsche, The RATIP program for relativistic calculations of atomic transition, ionization and recombination properties, Comput. Phys. Commun. 183 1525 (2012).