H21(1).mp4 Apr 2026

This content is part of a pedagogical resource focusing on teaching crystallographic symmetry, with related, comprehensive information available on the Bilbao Crystallographic Server. How the ? A deeper look into rhombohedral/hexagonal crystal packing ?

The minimum structural unit (the dimer) that, when acted upon by space group symmetry operations, generates the full crystal structure.

Three of these dimer units are arranged around a threefold rotation axis to form a hexamer, which takes the shape of an oblate spheroid. H21(1).mp4

These spheroids pack in a hexagonal system (rhombohedral shape) to form a crystal. The packing creates a "threefold symmetry axis" (Zn ions).

Animations, videos and 3D models for teaching space-group symmetry This content is part of a pedagogical resource

Zn ions, for example, are located directly on the rotation axis.

Insulin acts as a hormone that regulates blood glucose levels. The video highlights how this massive structure exists as a stable, inactive hexamer in the pancreas before dissociation into biologically active monomers. The minimum structural unit (the dimer) that, when

The video dv5020sup5.mp4 shows the "action of symmetry operations on the asymmetric unit," specifically how the atoms move, rotate, or translate. Key Concepts Illustrated in the Video