chapter
2 Pages

## U

Parallelepiped that can be found by dividing space with three nonparallel sets of planes passing through the

lattice points

of a

crystal lattice

.

Unit cell is chosen so that it has the same macroscopic

symmetry elements

as the

crystal system

of the lattice concerned. The unit cell shape is characterized by

fundamental translation vectors

,

a

,

b

, and

c

, directed along the cell edges. The lengths of these vectors,

a

,

b

, and

c

, respectively, are called unit cell parameters (constants), and the angles between the edges, known as axial angles, are denoted by

α

,

β

, and

γ

(see Figure U.2).