"DEEPEN will develop an integrated open source multiscale simulation environment, targeted at problems common to future nanoscale electronic and photonic devices. New device simulators require an atomic-scale description of selected critical regions of a transistor or LED to capture details otherwise inaccessible. They must also resolve the considerable uncertainty in many critical parameters required for device optimisation. DEEPEN addresses both these issues, coherently combining state-of-the-art existing methods and developing new methodologies, integrated within a multiscale framework spanning from first-principles to macroscopic models.DEEPEN brings together leading groups with expertise not just in simulation, but also in its application to device design and optimization. It builds on Tyndall and ETHZ expertise in material and device properties, with experimental input from PDI also critical for validation of the multiscale models developed. Industry partners include a key multiscale modelling system provider (TiberLAB), a leading TCAD simulation provider (Synopsys) and an industrial end-user (Osram) who provide experimental validation and test the simulation environment for device design and investigation. Future code distribution will be supported through the project web site and through TiberLAB’s existing support environment, www.tibercad.org.The nanoscale models to be developed address the challenging problem not just of predicting quantitatively electronic bands and quantum phenomena at the nanoscale, but also of linking these critical properties to overall device behaviour. The project emphasizes aggressive dissemination of results to maximize impact, including organization of Training Schools and an International Workshop, as well as the release and support of demonstration software and the open source interfaces. Overall, the project significantly strengthens European competitiveness, with clear routes to successful exploitation of the technology."