The objective of our research is to apply and develop computational tools to understand chemical reactions in biomolecules and organic molecules. On the application side our focus is on light-induced reactions, in particular in chromophore-protein complexes and solvated molecules. For this purpose we employ the QM/MM methodology which allows an accurate and efficient treatment of large systems. On the development side we have an interest in computational tools to support our research on photochemical/photobiological systems. We have contributions to several quantum chemistry packages with emphasis on multiconfigurational wavefunction methods.