code: def _read_mat_mnu0(filename):
      
      print('read_mag_single_file: {0}'.format(filename))
  
      mat = sio.loadmat(filename, squeeze_me=True)
      # check the version
      version = mat['MP']['Version'].item()
      if version != 'FZJ-EZ-2017':
          raise Exception(
              'This data format is not supported (expected: FZJ-EZ-2017)' +
              ' got: {}'.format(version)
          )
  
      df_emd = _extract_emd(mat, filename=filename)
      df_md = _extract_md(mat)
  
      return df_emd, df_md
docs: Import a .mat file with single potentials (a b m) into a pandas
      DataFrame
  
      Also export some variables of the MD struct into a separate structure