The face centered cubic (FCC) unit cell begins with a totally different layer ... Notice that the indentations are too close to one another for us to fill them all. In other words, if we were to place ...

Spinel, MgAl 2 O 4 (download cif), is a rare gemstone that was used to imitate rubies. The structure has face-centered cubic symmetry, and is a little heavy to understand. The general formula is AB 2 ...