The group has a strong expertise in Quantum Chemistry (QC) and related topics in theoretical chemistry. QC methods for large systems are developed and applied to a variety of chemical problems. Both, the computationally demanding methods of wave function theory as well as dispersion corrected density functionals (DFT-D4) are in the focus. For the treatment of very large systems and their dynamics or for the investigation of flexible systems in condensed phase we develop tight-binding MO methods (GFN-xTB) and force fields (GFN-FF) coupled with special search algorithms (CREST) and automated workflows (CENSO). All methods are constructed in a way that the main elements (H-Rn) are covered, chemical bonds can be broken or formed and all chemically relevant interactions are correctly described.