1 The practice of inventing mono-atomic structures in which atoms correspond with the nodes of the Bravais lattices led me to some web surfing. Such structures are, ipso facto, potential representations of the crystalline forms of the chemical elements. As you might intuitively expect, the crystalline form of most elements is either cubic or hexagonal. A few are orthorhombic, trigonal or tetragonal, three elements, P, Pu and Po are monoclinic, but none is triclinic.