17. Cu 3 Au is cubic with one Cu 3 Au molecule per unit cell. In an ordered form, the
atomic positions are: Au: (0, 0, 0), and Cu: (1/2, 1/2, 0), (0, 1/2, 1/2), (1/2, 0,
1/2). In the disordered form, the same positions are occupied at random. Taking
the case of disordered form and the indices h, k, l are all odd or all even, the
simplified structure factor is:
(a) (f Au - f Cu )
(b) (f Au - 3f Cu )
(c) (f Au + f Cu )
(d) (f Au + 3f Cu )
18. Cu 3 Au is cubic with one Cu 3 Au molecule per unit cell. In an ordered form, the
atomic positions are: Au: (0, 0, 0), and Cu: (1/2, 1/2, 0), (0, 1/2, 1/2), (1/2, 0,
1/2). In the disordered form, the same positions are occupied at random. Taking
the case of disordered form and the indices h, k, l are all odd or all even, the
corresponding intensity is:
(a) (f Au + f Cu )
2
(b) (f Au + 3f Cu )
2
(c) (f Au - f Cu )
2
(d) (f Au - 3f Cu )
2
19. When (h + k), (k + l), (l + h) are all even integers, the structure factor corresponding to a diamond cubic unit cell is:
(a) 2f C
(b) 4f C
(c) 6f C
(d) 8f C
20. When (h + k), (k + l), (l + h) are all even integers, the Intensity corresponding
to a diamond cubic unit cell is:
(a) 2f C
2
(b) 12f C
2
(c) 16f C
2
(d) 20f C
2
21. When (h + k + l) is an odd integer, the Intensity corresponding to a diamond
cubic unit cell is:
(a) 8f C
2
(b) 16f C
2
(c) 24f C
2
(d) 32f C
2
8.2 Determination of Phase Angle, Amplitude …
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