In these reactions, as the precursor concentration increases,
two trends become clear. One is that higher concentrations yield
larger structures and the other is that the level of branching seen
in the crystals increases with concentration. These can both be
explained by the additional molecular precursor material
remaining in the growth stages at the higher concentrations,
which may continue to grow additional material to the existing
crystal structures. Here, no additional shape control agent or
ligand is necessary to the formation of the various crystal