(c) 46.87°
(d) 56.87°
15. The side of a primitive cell of square lattice has a = 2 Å. A new unit cell is
chosen with edges defined by the vectors from the origin to the points with
coordinates 1, 0 and 0, 3. Area of the new unit cell is:
(a) 8Å
2
(b) 10Å
2
(c) 12Å
2
(d) 14Å
2
16. The side of a primitive cell of square lattice has a = 2 Å. A new unit cell is
chosen with edges defined by the vectors from the origin to the points with
coordinates 1, 0 and 0, 3. The number of lattice points in the new unit cell is:
(a) 6
(b) 5
(c) 4
(d) 3
17. A primitive tetragonal unit cell has a = 5 Å, b = 6 Å, and c = 7 Å; a = b =
= 90°. A new unit cell is chosen with edges defined by the vectors from the
origin to the points with coordinates: 3, 1, 0; 1, 2, 0 and 0, 0, 1.The lengths of
the three edges of the new unit cell are:
(a) 16.16 Å, 13 Å, 7 Å
(b) 15.16 Å, 12 Å, 7 Å
(c) 14.16 Å, 11 Å, 7 Å
(d) 13.16 Å, 10 Å, 7 Å
18. A primitive tetragonal unit cell has a = 5 Å, b = 6 Å, and c = 7 Å; a = b =
= 90°. A new unit cell is chosen with edges defined by the vectors from the
origin to the points with coordinates: 3, 1, 0; 1, 2, 0 and 0, 0, 1.The three angles
of the new unit cell are:
(a) a = b = c = 90°
(b) a = b = 90°, c = 45°
(c) a = b = 45°, c = 90°
(d) a = b = c = 45°
19. A primitive tetragonal unit cell has a = 5 Å, b = 6 Å, and c = 7 Å; a = b =
= 90°. A new unit cell is chosen with edges defined by the vectors from the
origin to the points with coordinates: 3, 1, 0; 1, 2, 0 and 0, 0, 1. Volume of the
new unit cell is:
(a) 839.84Å
3
(b) 939.84Å
3
130
3 Unit Cell Calculations