Metal specimens
Introducing some common metals and their crystal structures. Analyzing a single crystal of such kind by Single crystal X-ray diffraction technique reveals data to solve the crystal structures.
Bismuth (Bi) is a metal in group 15, and it crystalizes in rhombohedral crystal system with space group R-3m. Bismuth crystal has metallic iridescence color with distinctive shapes.
A Bi centered B6 octahedron shares edges to the neighbor octahedra to form a layer in (110) plane. The layers stack along [001] direction to form 3-dimentional Bismuth structure.
Silicon (Si) is an element in group 14, and it crystalizes in cubic fcc packing, space group Fd-3m. Silicon crystal has a blue-grey metallic luster in color, in bulky shape.
A Si centered Si4 tetrahedron shares corners to the neighbor tetrahedra to form 3-dimentional diamond network Si structure.