This is the atomic structure of quartz, a low-pressure polymorph of SiO2. In each tetrahedron, a silicon atom is located at the center and four oxygen atoms are at the vertices. By printing this model, you can understand the characteristics of quartz structure such as: This stl file is made by Blender with a self-made python script. All atoms are supported by cylinders to avoid using automatic supports, which is cumbersome to remove in my 3D printer.This model was printed using the Cube 3 printer without automatic support material. After printing, I removed vertical cylinders, which are self-made supports.