Crystal Structures, rotable 3D models

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Crystal Structures

Space lattices and crystals	A perfect crystal is considered to be constructed by a space lattice, i.e. by infinite regular repetition in space of identical structure units. Thus, the ideal crystal is invariant under translation in steps of lattice constants and related distances. It is also invariant under rotation in steps of well defined angles. There are 230 basic different repetitive patterns. Here we present some of the most important crystal structures. By mouse clicking, you can investigate their symmetry properties (e.g. 3-fold rotation axis, 4-fold rotation axis, mirror planes, etc.).
Manipulate a crystal	To rotate a crystal model, click on the selected crystal model and drag the mouse. You can also translate the model by dragging with pushed Ctrl key, or magnify it by dragging with pushed Shift key. You may also rotate the coordination models by dragging the mouse
CsCl structure	In the cesium chloride (CsCl) structure, the space lattice is simple cubic. There are two such simple cubic lattices which are separated by one half of the body diagonal of the unit cube. One lattice is occupied by Cs atoms, the other by Cl atoms. Each atom has 8 nearest neighbors of the opposite kind and is bound to these 8 atoms which are arranged at the corners of the surrounding hexahedron (cube). The bonding is typically ionic.
NaCl structure	In the natrium chloride (NaCl) structure, the space lattice is face centered cubic (FCC). There are two such FCC lattices which are separated by one half of the body diagonal of the unit cube. One lattice is occupied by Na atoms, the other by Cl atoms. Each atom has 6 nearest neighbors of the opposite kind and is bound to these 6 atoms which are arranged at the corners of the surrounding octahedron. The bonding is typically ionic.
ZnS structure	In the zinc blende (ZnS) structure, the space lattice is face centered cubic (FCC). There are two such FCC lattices which are separated by one quarter of the body diagonal of the unit cube. One lattice is occupied by Zn atoms, the other by S atoms. Each atom has 4 nearest neighbors of the opposite kind and is bound to these 4 atoms which are arranged at the corners of the surrounding tetrahedron. The bonding is typically covalent.
Diamond structure	The diamond structure is identical to the ZnS structure, exept that both lattices are occupied by the same kind of atoms. For diamond these atoms are C, in case of the elemental semiconductors Si or Ge. Without Si (Silicon), modern information technology would not exist: We live in the Silicon age!
See also	Double-Shell PSE Table of elements (HTML) with special columns highlighted Double-Shell PSE: Extended description Platonic Spheres - 3D rotatable models
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