code: public void transfToOriginCell(Tuple3d pt) {
  		transfToCrystal(pt);
  
  		// convert all coordinates to [0,1) interval
  		pt.x = pt.x<0 ? (pt.x%1.0 + 1.0)%1.0 : pt.x%1.0;
  		pt.y = pt.y<0 ? (pt.y%1.0 + 1.0)%1.0 : pt.y%1.0;
  		pt.z = pt.z<0 ? (pt.z%1.0 + 1.0)%1.0 : pt.z%1.0;
  
  		transfToOrthonormal(pt);
  	}
docs: Converts the coordinates in pt so that they occur within the (0,0,0) unit cell
  @param pt