Bravais
in 1848 had shown that all crystal structure can be generated by using only 14 types of unit cell or space lattice (lattice means well decorated structure). These lattices are known as Bravais lattices.
Bravais lattices are a concept in crystallography that describes the arrangement of atoms in a crystal lattice. A Bravais lattice is a set of points in three-dimensional space which is generated by a set of lattice vectors. These lattice vectors represent the basic repeating unit of the crystal structure, and they can be used to describe the symmetry of the lattice.
There are 14 possible Bravais lattices in three dimensions, which can be categorized into seven crystal systems: cubic, tetragonal, orthorhombic, monoclinic, triclinic, rhombohedral, and hexagonal. Each Bravais lattice is characterized by its lattice parameters, which include the length and angles between its lattice vectors.
We can classify all the Bravais lattices
into following types-
These 14 types of unit cells will give
rise to 230 types of lattice structures (space group) by performing such
symmetry operations as:
- Translation
- Rotation
- Translation + Rotation and
- Reflection
The concept of Bravais lattices is important in the study of crystal structures and their physical properties, as it provides a systematic way to describe and analyze the symmetry of different crystal structures. The Bravais lattice also plays a role in determining the diffraction patterns observed in X-ray crystallography, which can be used to determine the arrangement of atoms in a crystal.
In summary, Bravais lattices are a fundamental concept in crystallography that describe the arrangement of atoms in a crystal lattice. Understanding the properties and symmetry of Bravais lattices is important in the study of crystal structures and their physical properties.