Crystal Structure
[table id=5 /]
Crystal Structure |
A brief detail with examples |
Co-rdination Number |
Formula units per unit Cell |
NaCl TypeRock-Salt |
Na+ ions occupy the Octahedral sites while Cl– ions are in ccp arrangement or vice versa eg. NH4Cl, AgCl, AgBr, Halides of Li, Na &Rb; CaC2 etc. |
Na+ = 6 Cl– = 6 |
4 |
CsCl Type |
Cs+ ions occupy cubic sites while Cl– ions are at the corners of a cube or vice versa. |
Cs+ = 8 Cl– = 8 |
1 |
CaF2Type Fluorite Structure |
Ca2+ ions are in ccp while F– ions occupy Tetrahedral sites e.g. CaF2, BaF2, BaCl2, SrF2 etc. |
Ca2+ = 8 F – = 4 |
4 |
ZnS-Type a) Zinc blende
|
Zn2+ ions occupy Alternate tetrahedral sites e.g. while S2- ions are in the ccp e.g. ZnS, CuCl, CuBr,CuI, AgI etc. |
Zn2+ = 4 S2- = 4 |
4 |
b) Wurzite |
Zn2+ ions occupy Alternate tetrahedral sites while S2- ions are in hcp type of arrangement. |
Zn2+ = 4 S2- = 4 |
4 |
AntifluoriteStructureNa2O |
Positive ions occupy all the tetrahedral sites while Negative ions are in ccp type of arrangement. e.g. Na2O |
Na+ = 4 O2- = 8 |
4 |