Crystal Structures

A crystal is constructed by the infinite repetition of identical structural units in space. In the simplest crystals, the structural unit is a single atom. The structure of all crystals can be described in terms of a lattice, with a group of atoms attached to every lattice point. The group of atoms is called the basis.

The basis consists of a primitive cell, containing one single lattice point. Arranging one cell at each lattice point will fill up the entire crystal. There are several types of crystal structures. We show you the simplest structures. A crystal family is determined by lattices and point groups. It is formed by combining crystal systems which have space groups assigned to a common lattice system. In total, there are crystal families: triclinic, monoclinic, orthorhombic, tetragonal, hexagonal and cubic.