#g2 f3 % bravais group to g
6	% generator
 0 0 0 0 0 1
 0 0 0 0 1 0
 0 0 0 1 0 0
 0 0 1 0 0 0
 0 1 0 0 0 0
 1 0 0 0 0 0
6	% generator
 1  0  0  0  0  0
 1 -1  0  0  0  0
 0  0  0  0  0 -1
 0  0  0  0 -1  0
 0  0  0 -1  0  0
 0  0 -1  0  0  0
6x0	% invariant form
  2
 -1 2
  0 0  2
  0 0 -1 2
  0 0  0 0  2
  0 0  0 0 -1 2
6x0	% invariant form
  0
  0 0
  1 0  0
 -1 1  0 0
  0 1  1 0 0
 -1 0 -1 1 0 0
6x0	% invariant form
  0
  0 0
  0 1  0
 -1 0  0 0
  1 0  0 1 0
 -1 1 -1 0 0 0
2^2  * 3^2   = 36 % order of the group
