In `CaF_(2)` type (fluorite structure) `Ca^(2+)` ions form W structure and `F^(-)` ions are present in all X voids. The coordination number of `Ca^(2=)` is Y and `F^(-)` is Z. W,X,Y and Z respectively are

Options

A. `{:(W,X,Y,Z),(c cp, "octahedral",8,4):}`
B. `{:(X,X,Y,Z),( bc c,"tetrahedral" ,4,8):}`
C. `{:(X,X,Y,Z),( bc c,"tetrahedral" ,4,8):}`
D. `{:(X,X,Y,Z),( bc c,"octdedral" ,4,8):}`

Answer

C

Explanation

`Ca^(2+)` ion from ccp structure while `F^(-)` ions are in all tetrahedral holes and coordination in number are 6 and 4.