CSGI is actively involved in the theoretical rationalization and computational modelling of complex colloidal systems. State-of-the-art quantum-mechanics is applied to achieve in-depth characterization of the functional properties of both natural and synthetic nanomaterials. Computational methods are developed for the design of new materials with tailored physicochemical characteristics for applications in research fields as diverse as material science, environmental science and life science. The main activity of CSGI in this field is the development of valuable computational methods able to provide a fundamental characterization, at different lengthscales and from different structural and physicochemical perspectives, of new complex materials. The combination of theoretical and experimental approaches, adopted at CSGI, is key to provide convincing answers to the need of advanced tools for the design, development and characterization of complex colloidal systems.