[ Volume ] section
==================================================

Volume for cell ( :math:`\mathrm{cm^3}` ) can be defined in this section. 
If the volume is double defined, the value defined in this section is 
used. 
The volume is utilized in the tally sections. 
If you do not set volume, :math:`1.0\ \mathrm{cm^3}` volume.

The format is as follows.

.. code-block:: text

  [ Volume ]
    reg                 vol
    1                   1.000000    
    11                  5.000000    
    ( { 2 - 5 } 8 9 )   2.000000    
    ( 11 12 15 )        3.000000 
    16                  6.000000    
    ...                 ...
    ...                 ...

You can use the format ( { 2 - 5 } 8 9 ) for a group. 
In this case, you need to close a value by (  ) , if it is not a single numeric value. 

You cannot use the lattice and universe style as ( 6 < 10[1 0 0] < u=3 ).
If you want to set cell volume in detail, use the volume definition in the tally section. 

If you want to change the order of region number (reg) and volume (vol), you can set as vol reg. 
You can use the skip operator non.