docs: def getMetastable(rates, ver: np.ndarray, lamb, br, reactfn: Path):
      with h5py.File(reactfn, 'r') as f:
          A = f['/metastable/A'][:]
          lambnew = f['/metastable/lambda'].value.ravel(order='F')  # some are not 1-D!
  
      """
      concatenate along the reaction dimension, axis=-1
      """
      vnew = np.concatenate((A[:2] * rates.loc[..., 'no1s'].values[:, None],
                             A[2:4] * rates.loc[..., 'no1d'].values[:, None],
                             A[4:] * rates.loc[..., 'noii2p'].values[:, None]), axis=-1)
  
      assert vnew.shape == (rates.shape[0], A.size)
  
      return catvl(rates.alt_km, ver, vnew, lamb, lambnew, br)