CSSI Element: A General and Effective B-Spline R-Matrix Package for Charged-Particle and Photon Collisions with Atoms, Ions, and Molecules

This project concerns the development and subsequent distribution of a suite of computer codes that can accurately describe the interaction of charged particles (mostly electrons) and light (mostly lasers and synchrotrons) with atoms and ions. The results are of importance for the understanding of fundamental collision dynamics, and they also fulfill the urgent practical need for accurate atomic data to model the physics of stars, plasmas, lasers, and planetary atmospheres. Such studies can now be conducted for realistic systems, as opposed to idealized models. In particular, it has become possible to describe very complex targets, such as transition metals and other open-shell systems. Examples include the excited states of the inert gases beyond helium, as well as neutral and lowly-ionized iron. These systems are of significant importance for plasma diagnostics and astrophysics, respectively. The source code will be made publicly available. A website devoted to user-developer interaction will be developed and maintained together with the necessary code documentation and training materials.