NCS operators refinement in X-PLOR

[Pedro M. Matias]

Hi, all.

I am refining a protein structure with 4-fold NCS (2 dimers) However,
because the two molecules in each dimer actually form chemical bonds
between each other (not S-S) I have to do the refinement as a 
combination between NCS restraints (dimer) and strict NCS constraints
(between 1st and 2nd dimer).

My question is, how can I refine the strict NCS operator ?

Thanks in advance,

Pedro Matias