Structure of Ionic Crystals
Table: Types of ionic crystal with description
| Crystal structure type | Brief description |
Examples |
Co-ordination number | Number of formula units per unit cell |
|
Type AB Rock salt (NaCl) type |
It has fcc arrangement in which  ions occupy the corners and face centres of a cube while  ions are present at the body and edge of centres. |
Halides of Li, Na, K, Rb, AgF, AgBr, NH4Cl, NH4Br, NH4I etc. |
|
4
|
| Zinc blende (ZnS) type | It has ccp arrangement in which  ions form fcc and each  ion is surrounded tetrahedrally by four  ions and vice versa. |
 |
|
4 |
|
Type AB2 Fluorite (CaF2) type |
It has arrangement in which  ions form fcc with each  ions surrounded by  ions and each  ions by 4Ca2+ ions. |
  |
|
4 |
| Antifluorite type | Here negative ions form the ccp arrangement so that each positive ion is surrounded by 4 negative ions and each negative ion by 8 positive ions |  |
|
4 |
| Caesium chloride (CsCl) type | It has the bcc arrangement with  at the body centre and ions at the corners of a cube or vice versa. |
  and  |
|
1
|
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