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Example 2

Let G be the group generated by the two matrices below. How do the Z-classes in the Q-class of G distribute into their Bravais flocks? In particular, how many Bravais flocks are involved?
6
0 1 0 0 0 0
1 0 0 0 0 0
0 0 0 1 0 0
0 0 1 0 0 0
0 0 0 0 1 0
0 0 0 0 0 1
6
0 0 1 0 0 0
0 0 0 1 0 0
0 0 0 0 1 0
0 0 0 0 0 1
1 0 0 0 0 0
0 1 0 0 0 0

Used Programs

Bravais_catalog/Datei, Bravais_type, Is_finite, Order, Symbol, QtoZ

Solution

  1. Write the two matrices in a file 'G' and add
      #g2
    
    or
      #2
    
    as top row.
  2. Call
       Symbol G
    
    to compute the family symbol of the group in G.
    It turns out to be 3;2-2;1 .
  3. Call
       Bravais_catalog
    
    and input the symbol '3;2-2;1'. It says that there are 3 homogeneously decomposable Bravais groups in the family and that there are altogether 6 + 8 + 4 Z-classes of Bravais groups. Don't calculate the Bravais groups.
  4. Call
       Order -o G >> G
    
    It adds a bootom line to the file 'G' containing the order of the group G in factorized form to prepare the file as input for QtoZ.

    Alternatives:

    1. Is_finite -o G >> G has the same effect, but works faster.
    2. Order -O G produces a slightly more complete file, containing all the necessary information.
  5. Call
       QtoZ -D G
    
    Here the Q-class of the group G is split up into Z-classes. It turns out that there are 18 Z-classes. Because of the -D-option the representative groups are put into the following files

    G.1.1G.1.2 G.1.3G.1.4 G.1.5G.1.6 G.1.7G.1.8
    G.2.1G.2.2 G.2.3G.2.4 G.2.5G.2.6
    G.3.1G.3.2 G.3.3G.3.4

  6. Call
       Bravais_type G.1.1 > type.G.1.1
    
    etc. to
       Bravais_type G.3.4 > type.G.3.4
    
    to compute the Bravais group in the Bravais catalog which is Z-equivalent to the Bravais group of the group in G.1.1, etc. to G.3.4:

    type.G.1.1type.G.1.2 type.G.1.3type.G.1.4 type.G.1.5type.G.1.6 type.G.1.7type.G.1.8
    type.G.2.1type.G.2.2 type.G.2.3type.G.2.4 type.G.2.5type.G.2.6
    type.G.3.1type.G.3.2 type.G.3.3type.G.3.4

    It turns out that each Bravais type in the family is represented with multiplicity one.

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last change: 11.09.2000