9VARIABLES: cross_oi_rdc - CYANA variable

Initial value: 0

If this variable is set to 0, then orientation independent RDC
orientation independent RDC restraints are formed only from pairs of
conventional RDC restraints of the same type. If this variable is set
to 1, then orientation independent RDC restraints are formed also from
pairs of conventional RDC restraints that belong to different types,
e.g. H-N and HA-CA.
