Sorry not my field! But I would first give NAUTY[1] a try before trying more exotic, structure-exploiting stuff. [1] http://www3.cs.stonybrook.edu/~algorith/im

Sorry not my field! But I would first give NAUTY[1] a try before trying more exotic, structure-exploiting stuff. [1] http://www3.cs.stonybrook.edu/~algorith/implement/nauty/implement.shtml http://www3.cs.stonybrook.edu/~algorith/implement/nauty/impl...