11. A monoclinic unit cell of 1
st setting has the following parameters: a = 5Å, b =
10Å, c = 15Å, a ¼ b ¼ 90
and c ¼ 120
: The corresponding reciprocal lattice
parameters in the unit of (Å
−1 ) are:
(a) 0.23, 0.12, 0.08
(b) 0.20, 0.12, 0.08
(c) 0.23, 0.10, 0.08
(d) 0.23, 0.12, 0.07
12. A monoclinic unit cell of 1
st setting has the following parameters: a = 5Å, b =
10Å, c = 15Å, a ¼ b ¼ 90
and c ¼ 120
: The reciprocal cell volume is:
(a) 1.33Â10
−3
Å
3
(b) 1.43Â10
−3 Å
3
(c) 1.53Â10
−3
Å
3
(d) 1.63Â10
−3
Å
3
13. The primitive translation vectors of a simple hexagonal space lattice may be
taken as
A ¼
a
2
^ i þ
ffiffi ffi
3
p
a
2
^ j
; B ¼ À
a
2
^ i þ
ffiffi ffi
3
p
a
2
^ j
and C ¼ c ^ k
where ^ i, ^ j and ^ k are unit vectors. The reciprocal unit cell volume is:
(a)
2p
ð Þ
3
ffiffi
3
p a
2 c
(b)
2 2p
ð Þ
3
ffiffi
3
p a
2 c
(c)
3 2p
ð Þ
3
ffiffi
3
p a
2 c
(d)
4 2p
ð Þ
3
ffiffi
3
p a
2 c
14. The reciprocal lattice to a simple cubic (sc) lattice is:
(a) sc
(b) bcc
(c) fcc
(d) Dc
15. The reciprocal lattice to a body-centered cubic (bcc) lattice is:
(a) sc
(b) bcc
(c) fcc
(d) Dc
2.4 Fermi Surface and Brillouin Zone
89