Variations in abundance of known crystalline compounds as a function of lattice constants

Preliminary plots of the abundance of inorganic compounds as a function of their crystallographic parameters disclosed sharp peaks. A plot of cubic compounds as a function of the unit-cell length yielded numerous peaks which appeared to correspond to sets of structure types. For hexagonal compounds as a function of c/a, there were two peaks at about 1.0 and 1.6. The abundance of tetragonal compounds as a function of c/a yielded numerous peaks which did not obviously correspond to any specific structure types.