code: def find_structure(self, filename_or_structure):
          
          try:
              if isinstance(filename_or_structure, str):
                  s = Structure.from_file(filename_or_structure)
              elif isinstance(filename_or_structure, Structure):
                  s = filename_or_structure
              else:
                  raise MPRestError("Provide filename or Structure object.")
              payload = {'structure': json.dumps(s.as_dict(), cls=MontyEncoder)}
              response = self.session.post(
                  '{}/find_structure'.format(self.preamble), data=payload
              )
              if response.status_code in [200, 400]:
                  resp = json.loads(response.text, cls=MontyDecoder)
                  if resp['valid_response']:
                      return resp['response']
                  else:
                      raise MPRestError(resp["error"])
              raise MPRestError("REST error with status code {} and error {}"
                                .format(response.status_code, response.text))
          except Exception as ex:
              raise MPRestError(str(ex))
docs: Finds matching structures on the Materials Project site.
  
          Args:
              filename_or_structure: filename or Structure object
  
          Returns:
              A list of matching structures.
  
          Raises:
              MPRestError