Pearson-Symbol

The Pearson symbol is used for the structural description of crystalline matter and thus to map a geometric arrangement of atoms, molecules and ions in solid materials on a short string. The symbol contains this code for the crystal system and Bravais lattice, as well as an indication of the number of belonging to a unit cell atoms.

The Pearson symbol has the structure XYI. Where x is an abbreviation for the crystal system, Y is a symbol for the Bravais lattice and i mean a single-or multi-digit number and thus describe the number of atoms in the unit cell. In general, X and Y in italics, for example, is the Pearson symbol for solid copper CF4, for crystalline sodium chloride cF8.

The Pearson symbol can also be used to describe allotropic modifications in chemical formulas or material designations. For this purpose the symbol in brackets should be added directly after the corresponding expression. Ferritic α - iron can be used as iron ( CI2 ) and austenitic γ - iron are described as iron ( CF4).

Orthorhombic

Tetragonal