1 The following structure types are based on hexagonal or cu

1) The following structure types are based on hexagonal or cubic close-packing and the filling of octahedral sites or tetrahedral sites. For each phase, identify (1) close-packed atom, (2) the type of close packing (3) the geometry and (4) fraction of sites filled. (0.5 point for each, 6 pts in total) 6 NiAs, ZnS (zinc blende), Cal

Solution

ZnS   

1. close packing atom is zinc and sulpuur

2. type of close packing is F C C

3. geometry is tetrahedral

4. fraction of sites is 74%

CdI₂     

1. close packing atom isCd and I

2. type of close packing is hexagonal close packing

3. geometry is octrahedral

4. fraction of sites is 74%

NiAs   

1. close packing atom is Ni and As

2. type of close packing is F C C

3. geometry is octrahedral

4. fraction of sites is 74%