data_try_loop_with_single_quotes

    loop_
    _item_units_conversion.from_code
    _item_units_conversion.to_code
    _item_units_conversion.operator
    _item_units_conversion.factor
###
     'centimetres'              'millimetres'              '*'   1.0E+01
     'centimetres'              'nanometres'               '*'   1.0E+07
     'centimetres'              'angstroms'                '*'   1.0E+08
     'centimetres'              'picometres'               '*'   1.0E+10
     'centimetres'              'femtometres'              '*'   1.0E+13
#
     'millimetres'              'centimetres'              '*'   1.0E-01
     'millimetres'              'nanometres'               '*'   1.0E+06
     'millimetres'              'angstroms'                '*'   1.0E+07
     'millimetres'              'picometres'               '*'   1.0E+09
     'millimetres'              'femtometres'              '*'   1.0E+12
#
     'nanometres'               'centimetres'              '*'   1.0E-07
     'nanometres'               'millimetres'              '*'   1.0E-06
     'nanometres'               'angstroms'                '*'   1.0E+01
     'nanometres'               'picometres'               '*'   1.0E+03
     'nanometres'               'femtometres'              '*'   1.0E+06
#
###
     'celsius'                  'kelvins'                  '-'     273.0
     'kelvins'                  'celsius'                  '+'     273.0
###
     'electrons_per_nanometres_cubed'
     'electrons_per_angstroms_cubed'                       '*'   1.0E+03
     'electrons_per_nanometres_cubed'
     'electrons_per_picometres_cubed'                      '*'   1.0E+09
#
     'electrons_per_angstroms_cubed'
     'electrons_per_nanometres_cubed'                      '*'   1.0E-03
     'electrons_per_angstroms_cubed'
     'electrons_per_picometres_cubed'                      '*'   1.0E+06
#
     'electrons_per_picometres_cubed'
     'electrons_per_nanometres_cubed'                      '*'   1.0E-09

#...
#
