The school focuses on the modeling of large and complex (bio)chemical systems, ranging from molecules in solution to membrane-embedded proteins. The large size of such systems and the long time scale of chemically relevant phenomena necessitates the use of a combination of complementary techniques allowing to span multiple temporal and spatial scales. The school is aimed at young and more experienced researchers who will be taught advanced simulation techniques including multiscale and rare event sampling methods. The school covers methods for coupling different spatial resolutions using hybrid quantum mechanics/molecular mechanics (QM/MM) models [1] and multiple time scales through multiple time step (MTS) algorithms [2] as well as sampling methods for reconstructing free energy surfaces, identifying reaction paths, and computing process/reaction rates [3]. The theoretical lectures will be complemented by practical sessions where the multiscale modeling framework MiMiC [4-6] will be used. This also includes training in the efficient use of HPC resources, e.g., how to setup a simulation to optimize efficiency.