The effective number of lattice points in the unit cell of simple
| The effective number of lattice points in the unit cell of simple cubic, body centered cubic, and face centered cubic space lattices, respectively, are
A. 1,2,2
B. 1,2,4
C. 2,3,4
D. 2,4,4
Please scroll down to see the correct answer and solution guide.
Right Answer is: B
SOLUTION
Concept:
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Diagram |
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Effective no. of lattice points |
\(\Rightarrow \frac{1}{8} × 8 = 1\) |
\(\frac{1}{8} × 8 + 1 = 2\) |
\(\frac{1}{8} × 8 + \frac{1}{2} × 6 = 4\) |
In the unit cell effective number of atoms = corner atoms × (1/8) + face cantered atoms × (1/2) + 1 (Inner atom)
|
Unit Cell |
Coordination No. |
No. of Atoms Per Unit Cell |
Atomic packing factor |
|
Simple Unit Cell |
6 |
1 |
52% |
|
Body-centred Cubic |
8 |
2 |
68% |
|
Face-centred Cubic |
12 |
4 |
74% |
|
Hexagonal Closest Packed |
12 |
6 |
74% |
