Questions
Quick questions
You should be able to answer these questions without too much difficulty after studying this TLP. If not, then you should go through it again!
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Which of these is not a lattice type ?
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What is a lattice ?
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How many Bravais lattices (3D) are there ?
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How many point groups (3D) are there ?
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What is a unit cell ?
Deeper questions
The following questions require some thought and reaching the answer may require you to think beyond the contents of this TLP.
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Construct a plan view of NaCl (sodium chloride).
NaCl has a face-centred cubic lattice. The motif is:
Cl @ (0,0,0);
Na @ (0,0,1/2);
Note 1: The motif coordinates are positions relative to each lattice point
Note 2: In a face centred cubic structure the lattice points are located at:
(0,0,0), (1/2,1/2,0), (1/2,0,1/2), (0,1/2,1/2) -
Diamond has a face centred cubic lattice. Its motif is
C @ (0,0,0), (1/4,1/4,1/4)
Construct a plan view of the diamond unit cell.
Treating the carbon atoms as hard spheres calculate the packing efficiency of diamond.
Note: In a face centred cubic structure the lattice points are located at:
(0,0,0), (1/2,1/2,0), (1/2,0,1/2), (0,1/2,1/2)