Zn ions, for example, are located directly on the rotation axis.
Animations, videos and 3D models for teaching space-group symmetry H21(1).mp4
The core topic is as a complex macromolecule. Deep Dive: Insulin Dimer as a Giant Asymmetric Unit Zn ions, for example, are located directly on
These spheroids pack in a hexagonal system (rhombohedral shape) to form a crystal. The packing creates a "threefold symmetry axis" (Zn ions). H21(1).mp4
Three of these dimer units are arranged around a threefold rotation axis to form a hexamer, which takes the shape of an oblate spheroid.