International
Tables for
Crystallography
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

International Tables for Crystallography (2006). Vol. C, ch. 9.1, p. 749

Figure 9.1.1.3 

E. Kocha and W. Fischera

aInstitut für Mineralogie, Petrologie und Kristallographie, Universität Marburg, Hans-Meerwein-Strasse, D-35032 Marburg, Germany

[Figure 9.1.1.3]
Figure 9.1.1.3

Two square nets representing two layers of spheres stacked in such a way that each sphere is in contact with four spheres of the other layer.