Bravais Space Lattice
Bravais shows that only 14 types of space
lattice are possible.
Igure shows the 14 Bravais lattices.
The 14 lattices are ground into grouped into
seven crystal systems.
Rom the figure it is clear that seven sets of
axes are sufficient to construct the 14 Bravais lattices. This leads to
classification of all crystals into seven crystal systems.
1) Cubic 2) Tetragonal 3) Ortho-Rhombic 4)
Monoclinic 5) Triclinic 5) Triclinic 6) Trigonal (Sometimes) called
Rhombohedral and 7) Hexgonal. Table 3.3.1 gives the seven crystal systems,
divided into fourteen Bravais Lattices. Note that a simple lattice has points
only at the corners, a body – centered lattice has only one additional point at
the center of the cell, and a ace-centered lattice has six additional points,
one on each face.
The Seven Crystal Systems divided into
Fourteen Bravais Lattices
Lattice is defined as an array of points which
are imaginarily kept to represent the position of atoms in the crystal that
every lattice point has got the same environment as that o the other and hence
one lattice point cannot be distinguished from the other lattice point.
Space Lattice or Crystal Lattice is a three
dimensional collection of points in space. The environment about any particular
point is in everyway the same.