4-2a

#g5 f1 % almost decomposable bravais-group
4	% generator
 1  0 0 0
 0 -1 1 0
 0  0 1 0
 0  0 0 1
4	% generator
  1 0  0 0
  0 0 -1 1
 -1 0 -1 0
 -1 1 -1 0
4	% generator
  0 -1 0 0
  0 -1 1 0
 -1 -1 1 0
  0  0 0 1
4	% generator
  0 -1 0 0
 -1  0 0 0
 -1 -1 1 0
  0  0 0 1
4	% generator
 1 -1  0 1
 0  1 -1 1
 0  2 -2 1
 0  2 -1 0
4	% invariant form
  4  0 -1  3
  0  6 -3  0
 -1 -3  4 -3
  3  0 -3  6
2^4  * 3^2   = 144 % order of the group