Simple crystal structure

NaCl structure is shown in Fig.12
•The lattice is FCC
•The basis is consists of 1Na+ ion and 1Cl- ion separated by ½ the diagonal of a unit cube.
•There are 4 units in each unit cube.
• The coordination number of NaCl is 6
•The coordinates of atoms in unit cube are
0,0,0 ; ½,½,0; ½,0,½; 0, ½,½
½,½,½ ; 0,0, ½ ; 0, ½,0 ; ½,0,0
CsCl structure is shown in Fig.13
•The lattice is BCC
• The basis has 1 Cs+ ion at 0,0,0 and 1 Cl- ion at ½,½,½
• The coordination number of CsCl is 8
A close packed- layer of spheres (atoms) is shown in Fig. 14, with centers at points (A ). A second layer goes in over (B). A third layer (C) may be added in two ways: if it goes in over (A) the order is AB AB AB and the structure is hcp (see Fig. 14). Note:
The indices of the plane in hexagonal structure marked by (hkil), were i=-(h+k)
If it goes in over (C) the order is ABC ABC ABC and the structure is FCC.Diamond structure is shown in Fig.16
•The lattice is FCC
•The basis has 2 identical atoms at coordinates o,o,o and ¼,¼,¼.
•The coordinates of atoms in unit cube are