13. 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 the ordered 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 )
14. 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 the ordered form and the indices h, k, l are mixed, the simplified
structure factor is:
(a) (f Au - f Cu )
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(b) (f Au - 3f Cu )
(c) (f Au + f Cu )
(d) (f Au + 3f Cu )
15. 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 the ordered 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
16. 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 the ordered form and the indices h, k, l are mixed, 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
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8 Structure Factor Calculations