34. When (h + k + l) is an odd integer, the intensity corresponding to the unit cell
of ZnS having zinc blende structure is:
(a) 16[f Zn
2 + f S
2 ]
(b) 16[f Zn
2 - f S
2 ]
(c) [f Zn
2 + f S
2 ]
(d) [f Zn
2 - f S
2 ]
35. When (h + k + l) is an odd multiple of 2, the intensity corresponding to the unit
cell of ZnS having zinc blende structure is:
(a) 16[f Zn
2 + f S
2 ]
2
(b) 16[f Zn
2 - f S
2 ]
2
(c) [f Zn
2 + f S
2 ]
(d) [f Zn
2 - f S
2 ]
36. When (h + k + l) is an even multiple of2, the intensity corresponding to the
unit cell of ZnS having zinc blende structure is:
(a) [f Zn
2 + f S
2 ]
(b) [f Zn
2 - f S
2 ]
(c) 16[f Zn
2 + f S
2 ]
2
(d) 16[f Zn
2 - f S
2 ]
2
37. A unit cell of a tetragonal crystal has its atoms positioned at the following
locations: (0, 1/2, 1/4), (1/2, 0, 1/4), (1/2, 0, 1/2), (0, 1/2, 3/4). The structure
factor corresponding to (110) reflection is:
(a) 4f
(b) 2f
(c) -2f
(d) -4f
38. A unit cell of a tetragonal crystal has its atoms positioned at the following
locations: (0, 1/2, 1/4), (1/2, 0, 1/4), (1/2, 0, 1/2), (0, 1/2, 3/4). The intensity
corresponding to (110) reflection is:
(a) 20f
2
(b) 16f
2
(c) 12f
2
(d) 8f
2
39. CaF 2 (Fluorite) is a face-centered cubic with 4 CaF 2 molecules per unit cell.
The Ca and F ions are located at the following positions:
Ca : 0; 0; 0
ð
Þ; 1=2; 1=2; 0
ð
Þ ; 0; 1=2; 1=2
ð
Þ ; 1=2; 0:1=2
ð
Þ ;
F : 1=4; 1=4; 1=4
ð
Þ ; 1=4; 1=4; 3=4
ð
Þ ; 1=4; 3=4; 1=4
ð
Þ ; 3=4; 1=4; 1=4
ð
Þ ;
3=4; 3=4; 1=4
ð
Þ ; 3=4; 1=4; 3=4
ð
Þ ; 1=4; 3=4; 3=4
ð
Þ ; 3=4; 3=4; 3=4
ð
Þ
334
8 Structure Factor Calculations