code: def _set_translations(self):
          
  
          pcell = PhonopyAtoms(numbers=[1],
                               scaled_positions=[[0, 0, 0]],
                               cell=np.diag([1, 1, 1]))
          smat = self._supercell_matrix
          self._trans_s = get_supercell(pcell, smat).get_scaled_positions()
          self._trans_p = np.dot(self._trans_s, self._supercell_matrix.T)
          self._N = len(self._trans_s)
docs: Set primitive translations in supercell
  
          _trans_s
              Translations with respect to supercell basis vectors
          _trans_p
              Translations with respect to primitive cell basis vectors
          _N
              Number of the translations = det(supercel_matrix)