Module 4 : Solid State Chemistry
Lecture 17 : Closed Packed Structures
 

The location of sites a, b, and c is shown in Fig 17.1 and the packing according to HCP mode is shown in Fig 17.2.

a)

                       ababab (HCP)                                                       abcabc (CCP)
 
b)
 
c)
 
 
Figure 17.2 (a) Three layers of spheres showing HCP (i.e., abab layers) arrangement. Notice that the C layers are not occupied here. This figure is shown in flash mode and static mode. (b) Three layers of spheres showing FCC ( CCP ) (i.e., abcabc layers) arrangement. Notice that the C layers are occupied here, (c) FCC (abc layers) arrangement.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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