Final Activity Report Summary - ZEO-SIMULATION (A Molecular Investigation of Photocatalysis in Zeolites) We performed molecular simulations in zeolites and related nanoporous materials used as catalysts or adsorbents. Zeolites are solid materials at the forefront of nanotechnology. From a chemical and structural point of view, zeolites are nanoporous crystalline alumino-silicates with a rich variety of structures, compositions and industrial applications. The need to remove highly toxic compounds from air, soil and water with efficient catalysts is of increasing importance. Photocatalysis using zeolite catalysts is a relatively new process for the degradation of pollutants. The cavities in zeolites confine reactants to a particularly shaped space. Therefore, they act as a selective medium, leading the photochemical reactions to specific products. In a five years' project, which lasted from 2005 to 2009, we: 1. studied the interactions between the zeolites and the photosensitisers; 2. investigated adsorption and diffusion of substrates and sensitisers in zeolites; and 3. understood how the zeolite cages changed the photophysical properties of the sensitisers. Our main achievement during 2005 was the development of both new force fields and classical simulation approaches to study adsorption, diffusion and reaction in these structures. The development of these methods and sets of parameters was vital to initiate the second project part. By the time of the project completion we were using them to investigate the concentration of molecules at reaction conditions, the diffusion coefficient of several pollutants in a pore and the way in which the zeolite structure contributed to the free energy of the molecules located in the pores.