code: public boolean isPureTranslation() {
  		if (isPureCrystalTranslation()) return true;
  		if (SpaceGroup.deltaComp(matTransform.m00,1,SpaceGroup.DELTA) &&
  			SpaceGroup.deltaComp(matTransform.m01,0,SpaceGroup.DELTA) &&
  			SpaceGroup.deltaComp(matTransform.m02,0,SpaceGroup.DELTA) &&
  
  			SpaceGroup.deltaComp(matTransform.m10,0,SpaceGroup.DELTA) &&
  			SpaceGroup.deltaComp(matTransform.m11,1,SpaceGroup.DELTA) &&
  			SpaceGroup.deltaComp(matTransform.m12,0,SpaceGroup.DELTA) &&
  
  			SpaceGroup.deltaComp(matTransform.m20,0,SpaceGroup.DELTA) &&
  			SpaceGroup.deltaComp(matTransform.m21,0,SpaceGroup.DELTA) &&
  			SpaceGroup.deltaComp(matTransform.m22,1,SpaceGroup.DELTA) &&
  			(	Math.abs(matTransform.m03-0.0)>SpaceGroup.DELTA ||
  				Math.abs(matTransform.m13-0.0)>SpaceGroup.DELTA ||
  				Math.abs(matTransform.m23-0.0)>SpaceGroup.DELTA)) {
  			return true;
  		}
  
  		return false;
  	}
docs: Tells whether this transformation is a pure translation:
  either a pure crystal (lattice) translation or a fractional (within
  unit cell) translation: space groups Ixxx, Cxxx, Fxxx have operators
  with fractional translations within the unit cell.
  @return