Note 2.
When I speak about atoms with respect to crystals and crystallization, I mean the crystal constituents that (are going to) occupy the lattice locations (points) of the crystal. These could be atoms, but also ions, and also molecules (compounds of atoms). A lattice point can also sometimes not coincide with the position of a single atom. In that case the lattice point is just the location of a pattern of atoms, like a complex ion. The constituents of such a local pattern then can be grouped around the lattice point. In this way the lattice points are geometrical points which reflect the ordering of the crystal constituents.
back to main text .