code: def set_BSE_options(self, n_excitations=10, nit_bse=200):
          
  
          self.BSE_TDDFT_options.update(npsi_bse=n_excitations, nit_bse=nit_bse)
docs: Set parameters in cell.in for a BSE computation
          :param nv_bse: number of valence bands
          :param nc_bse: number of conduction bands
          :param n_excitations: number of excitations
          :param nit_bse: number of iterations