code: def symmetrically_add_atom(self, specie, point, coords_are_cartesian=False):
  
          
  
          # For now just use the species of the
          # surface atom as the element to add
  
          # Get the index of the corresponding site at the bottom
          point2 = self.get_symmetric_site(point, cartesian=coords_are_cartesian)
  
          self.append(specie, point, coords_are_cartesian=coords_are_cartesian)
          self.append(specie, point2, coords_are_cartesian=coords_are_cartesian)
docs: Class method for adding a site at a specified point in a slab.
              Will add the corresponding site on the other side of the
              slab to maintain equivalent surfaces.
  
          Arg:
              specie (str): The specie to add
              point (coords): The coordinate of the site in the slab to add.
              coords_are_cartesian (bool): Is the point in cartesian coordinates
  
          Returns:
              (Slab): The modified slab