A
crystallographic database is a database specifically designed to store information about the structure of
molecules and
crystals. Crystals are
solids having, in all three dimensions of space, a regularly repeating arrangement of
atoms,
ions, or
molecules. They are characterized by
symmetry,
morphology, and directionally dependent physical properties. A
crystal structure describes the arrangement of atoms, ions, or molecules in a crystal. (Molecules need to crystallize into solids so that their regularly repeating arrangements can be taken advantage of in
X-ray,
neutron, and
electron diffraction based
crystallography.)