CoachLattices are grouped by their symmetry into seven crystal systems (triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, cubic). A cell may hold lattice nodes only at its corners (primitive, P) or also at its centre (body-centred, I), at the centres of all faces (face-centred, F) or of one pair of faces (base-centred, C), or along a body diagonal (rhombohedral, R): this is its lattice centring. The 14 distinct combinations of a system and a centring are the Bravais lattices.
