gap> Orbifold:=ContractibleGcomplex("PGL(3,Z[i])");
Non-free resolution in characteristic 0 for matrix group . 
No contracting homotopy available. 

gap> R:=FreeGResolution(Orbifold,6);
Resolution of length 5 in characteristic 0 for matrix group . 
No contracting homotopy available. 

gap> Homology(TensorWithIntegers(R),5);
[ 2, 2, 2, 2, 2, 4, 4 ]
