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Periodic table (crystal structure) – (for elements that are solid at standard temperature and pressure) gives the crystalline structure of the most thermodynamically stable form(s) in those conditions. In all other cases the structure given is for the element at its melting point.
The following table gives the crystalline structure of the most thermodynamically stable form(s) for elements that are solid at standard temperature and pressure. Each element is shaded by a color representing its respective Bravais lattice, except that all orthorhombic lattices are grouped together.
For example, water can also form amorphous ice, while SiO 2 can form both fused silica (an amorphous glass) and quartz (a crystal). Likewise, if a substance can form crystals, it can also form polycrystals. For pure chemical elements, polymorphism is known as allotropy.
Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond as a form of carbon is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water.
Bismuth oxide, in its delta form, is a solid electrolyte for oxygen. This form normally breaks down below a high-temperature threshold, but can be electrodeposited well below this temperature in a highly alkaline solution. [99] Bismuth germanate is a scintillator, widely used in X-ray and gamma ray detectors. [100]
Generally, this structure is more likely to be formed from two elements whose ions are of roughly the same size (for example, ionic radius of Cs + = 167 pm, and Cl − = 181 pm). The space group of the caesium chloride (CsCl) structure is called Pm 3 m (in Hermann–Mauguin notation), or "221" (in the International Tables for Crystallography).
Compounds that consist of more than one element (e.g. binary compounds) often have crystal structures based on the hexagonal crystal family. Some of the more common ones are listed here. These structures can be viewed as two or more interpenetrating sublattices where each sublattice occupies the interstitial sites of the others.
Fundamentals of crystallography: crystal systems, Miller Indices, symmetry elements, bond lengths and radii, theoretical density; Crystal and glass structure prediction: Pauling's and Zachariasen’s rules; Phase diagrams and crystal chemistry (including solid solutions) Imperfections (including defect chemistry and line defects) Phase transitions