code: def get_nn_shell_info(self, structure, site_idx, shell):
          
  
          all_nn_info = self.get_all_nn_info(structure)
          sites = self._get_nn_shell_info(structure, all_nn_info, site_idx, shell)
  
          # Update the site positions
          #   Did not do this during NN options because that can be slower
          output = []
          for info in sites:
              orig_site = structure[info['site_index']]
              info['site'] = PeriodicSite(orig_site.species,
                                          np.add(orig_site.frac_coords,
                                                 info['image']),
                                          structure.lattice,
                                          properties=orig_site.properties)
              output.append(info)
          return output
docs: Get a certain nearest neighbor shell for a certain site.
  
          Determines all non-backtracking paths through the neighbor network
          computed by `get_nn_info`. The weight is determined by multiplying
          the weight of the neighbor at each hop through the network. For
          example, a 2nd-nearest-neighbor that has a weight of 1 from its
          1st-nearest-neighbor and weight 0.5 from the original site will
          be assigned a weight of 0.5.
  
          As this calculation may involve computing the nearest neighbors of
          atoms multiple times, the calculation starts by computing all of the
          neighbor info and then calling `_get_nn_shell_info`. If you are likely
          to call this method for more than one site, consider calling `get_all_nn`
          first and then calling this protected method yourself.
  
          Args:
              structure (Structure): Input structure
              site_idx (int): index of site for which to determine neighbor
                  information.
              shell (int): Which neighbor shell to retrieve (1 == 1st NN shell)
          Returns:
              list of dictionaries. Each entry in the list is information about
                  a certain neighbor in the structure, in the same format as
                  `get_nn_info`.