Graphitic Nanotubes are linear carbon structures with an increasing relevance in the nanotechnology sector because of its metallic or semiconductor behavior depending on their structure. In this topic, our group studies theoretically junctions of two or more of them, focusing interest in conductivity and the electronic structure. Side by side with these investigations, we perform calculations on interaction of metallic ions with graphitic systems, in order to understand the synthesis of nanotubes with metals included (That may show superconductor properties). The design of possible new electronic devices is also treated in our group.