Tielens’ group is interested in the investigation of physico-chemical properties of solids. The tools we use are those of quantum chemistry and more recently those of clacical force fields. Over the years we have been particularly interested in periodic density functional theory (DFT). The materials that we have studied can be grouped into three main categories: silica-based materials, noble metals and bio- and biological materials. The goal of our research is to characterize these complex materials at the atomic and molecular level. For this we build unique and calculable models. The properties derived from the obtained electron density have brought me to collaborate with experimentalists. In summary we are experts in the use of theoretical chemistry and computational chemistry through the use of DFT combined with experimental methods, to achieve this goal of characterization materials at the atomic/molecular level. Our main contribution until now, without any doubt is the development of the computational chemistry methods and techniques in silica chemistry, as can be verified in the CV and the citations associated to the keywords: Silica AND DFT. A second main contribution concerns the very first DFT calculation of mixed thiol SAMs on gold surfaces, which constituted the origin of our research line on Self Assembled Monolayers. We have a long tradition in collaborating with the different partners, demonstrated by the published papers. This enables us to face the future with the certainty of upholding a high level of quality, which may be defined as research excellence. This is demonstrated also by the fact that the research group of the VUB, ALGC to which the Materials Modeling Groups belongs was appointed strategic research group from the VUB. Very recently, we have been recognized with a seal of excellence from the European Union, but before we were implicated in several European funded research projects.