Nowadays, computer simulations play an important role in modern chemistry and biophysics. Simulations of chemical reaction pathways could provide an atomistic insight into many natural and technological processes. To perform such kind of modelling in complex systems that include solvent and/or proteins, Multi-scale Quantum Mechanics / Molecular Mechanics (QM/MM) approaches are often used. In this webinar, I will present the newly developed fully integrated QM/MM interface between the GROMACS molecular dynamics program and the CP2K quantum chemistry package. The new interface enables users to smoothly set up QM/MM models of their system and use all simulation techniques available in GROMACS to study the chemistry.