Volume of the unit cell. All the cells found by TRCELL are scaled to this
volume. In addition, manually specified cell parameters are scaled to this volume.
During the refinement of the cell parameters in indxpat, the volume of the unit
cell is kept constant at this value.
It is possible to index the Laue pattern using
an arbitrary volume: however, 
, 
and 
should
then also be determined on the same, arbitrary, scale.
format V, in Å
default volume 1000.0 example volume 1514984.1