Assertion: tetrahedral void | /r/HasProperty | formed
Facets:
Source sentences:
text: Wherever a sphere of the second layer is above the void of the first layer (or vice versa) a tetrahedral void is formed.
text: At other places, the triangular voids in the second layer are above the triangular voids in the first layer, and the triangular shapes of these do not overlap then the octahedral void is formed.