  Symmetries are so involved in crystallographic detail that it is
indispensable when crystal cell or lattice is mentioned. For nanocrystals,
however, many are 'systemic symmetries', meaning that the whole structures of
nanocrystal particles are symmetrical from a different view. In that case, the
development of the systemic symmetry is dictated by the law of symmetry
breaking; that is, nanocrystallization does, to some extent, exceed current
theories associated with crystallography.
