Hi, I'm looking for a tool (a kind of software) to build graphene shell and hollow structures as shown in the second and the last drawings in this image: http://origin-ars.sciencedirect.com/content/image/1-s2.0-S0021999111007042-gr11.jpg [Broken] (Image is from http://www.sciencedirect.com/science/article/pii/S0021999111007042) I can draw graphene layers with some tools such as VMD of Illionis. But I don't know how to connect the edges and what will the atomic positions be when folding and connecting the layers (Note the left edge connected in Step 1 of the above image). I don't know if a tool for this needs to be a sopisticated physics tool. It may just be a geometric tool to play with atomic positions and obtain the structure I need? Can you recommend such a computer tool please? Thanks in advance.