1. Layers of spheres in the square formation can build up to form the body-centred cubic structure. 2. Each sphere in a body-centred cubic structure is at the centre of a cube with spheres at each corner. 3. The caesium chloride structure, for example, consists of a cubic structure of cations and a cubic structure of anions. 4. Together they form two interpenetrating body-centred cubic structures. 5. Together they form two intersecting face-centred cubic structures. 6. The zinc blende type of structure has a face-centred cubic structure. 7. If we view this as a cubic structure of cations, then the anions have a tetrahedral structure inside the cube. 8. Alternatively, if we view the anions as the cubic structure then the cations have the tetrahedral arrangement. 9. It has a face-centred cubic structure. 10. Pilgrims will also circle the Kaaba, a cubic stone structure in Mecca, to which Muslims around the world turn for prayer. |