International CECAM Workshop & Tutorial on “Approximate Quantum Methods in the ab initio World” (DFTB2016) was successfully held in Beijing Computational Science Research Center, during 6^th -13^th November, 2016. The workshop was organized by ChiYung Yam (CSRC), Marcus Elstner (Karlsruhe Institute of Technology) and Thomas Frauenheim (University of Bremen), of which the objective is to facilitate communication and collaboration between users and developers of multi-scale quantum methods, and to provide a unique forum to bring together world leaders of different communities in method development to discuss recent advances in current methodologies, and to identify critical challenges in the field as well as future directions for research and development of the next generation of computational tools.

There are 26 professors from 12 different countries all over the world were invited to conduct tutorials and deliver the lectures which are aimed to help students and researchers in both first-principles and approximate quantum mechanical methods. In the tutorial session, participants gained the knowledge about efficient parameterization techniques, reference databases, and hand-on exercises on different applications. Simultaneously, the workshop had the speakers from the DFT and ab initio communities, who are interested in SE/DFTB methods as a supplement to their first principles codes. More than 60 participants attended DFTB2016 from Europe, USA and Asia.