Mixed Complex Bonding Crystal

In the crystal complex, plays a variety of atoms and the bond is a bond mix in many ways. The crystal structure thus can be understood when considering that the crystal is composed of a combination of coordination polyhedron, in which small stuan of the cation is surrounded by several anions. One example is a silicate which is an important raw material for ceramics.

The basic structure of the silicate is tetrahedron (SiO4) 4 -. Si-O bonds in coordination tetrahedron meet both the directional covalent bonds as well as comparisons of the relative atomic radius. There are various types of silicate structures for a variety of ways such combinations may happen SiO4 tetrahedron or between tetrahedron SiO2 with other ions. Because the magnitude of charge on the ion Si4 + and low coordination number, tetrahedron SiO4, rarely associated with the angle with him and never associated with the field with him.

A silicate in which each tetrahedron not connected to the other is called ortosilikat. Included in this group are olivine (Mg, Fe11) 2, (SiO4), and garnet (Mg, Fe11, Mn, Ca) 3, (Cr, Al, Fe111) 2, (SiO4) 3. In olivine, the oxygen ions form a hexagonal arrangement of meetings that the structure was distorted, while the silicon ion occupies the eighth place in the hexagonal tetrahedral them.