**Primitive cell** __Primitive cell:__ A primitive cell is a unit cell built on the basis vectors of a

primitive basis of the

direct lattice, namely a

crystallographic basis of the vector lattice L such that every lattice vector t of L may be obtained as an integral linear combination of the basis vectors, a, b, c.

It contains only one lattice point and its volume is equal to the triple scalar product (a, b, c).

Non-primitive bases are used conventionally to describe centred lattices. In that case, the unit cell is a multiple cell and it contains more than one lattice point. The multiplicity of the cell is given by the ratio of its volume to the volume of a primitive cell.

__Primitive basis:__ A primitive basis is a

crystallographic basis of the vector lattice L such that every lattice vector t of L may be obtained as an integral linear combination of the basis vectors, a, b, c.

__Crystallographic basis:__ A basis of n vectors e1, e2, ... , en of the vector space Vn is a crystallographic basis of the vector lattice L if every integral linear combination t = u1e1 + u2e2 + ... + unen is a lattice vector of L. It may or may not be a primitive basis.

__See also:__ Conventional cell

http://www.oraxcel.com/cgi-bin/yabb2/YaBB.pl?num=1350114490/0#0 Unit cell

http://www.oraxcel.com/cgi-bin/yabb2/YaBB.pl?num=1350114408 __Source:__ http://reference.iucr.org/dictionary/Primitive_cell http://reference.iucr.org/dictionary/Primitive_basis http://reference.iucr.org/dictionary/Crystallographic_basis