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
|
