code: def setup_explicit_indices_local_geometry(self, explicit_indices):
          
          self.icentral_site = 0
          self.indices = [ii + 1 for ii in explicit_indices]
docs: Sets up explicit indices for the local geometry, for testing purposes
          :param explicit_indices: explicit indices for the neighbors (set of numbers
          from 0 to CN-1 in a given order)