DESCRIPTION OF CRYSTALS STRUCTURES

Abstract

In general, the unit cell is described as a curved parallelepiped. All atoms located in it are called the basis of the unit cell of the crystal. There are specific laws for the construction of the unit cell and the basis, in particular, its degree of symmetry determines many of the electrical, magnetic, and mechanical properties of the crystal. The unit cell can contain one or several atoms. For example, in most metals, such as iron, chromium, copper, and silver, it contains only one atom. If a crystal is composed of several chemical elements, such as sodium and chlorine, then the elemental cell contains at least two atoms: sodium and chlorine. In addition, a unit cell is made up of a group of several interconnected molecules, such as ice crystals or a series of magnetic materials. There are also crystals with unit cells made up of molecules made up of several thousand atoms, such as compounds with blind molecules.