Prof. Ortmann's (*1980) research area is the theoretical modelling of ground and excited states and their time dynamics. Quantum theoretical so-called ab initio methods are developed and applied to different material systems. Current research topics include charge and spin transport, optical spectroscopy with excitonic effects, and the influence of the electron-phonon interaction. Typical material systems range from small molecules and polymers to organic mixed systems, crystals or novel 2D materials.