Hi, I tried updating some old refinement scripts that use the "sani" statement to incorporate RDC data, with fixed values of axial and rhombic terms that we get by fitting experimental RDCs to calculated structures in the PALES program. (I know there are better ways of doing this these days, but I was in a hurry). PALES outputs values that need to be corrected for the maximum dipolar couplings of a given spin pair. I used three sets of RDCs, N-NH, C'-Ca and N-C'. After the correction, the absolute values of A and Rh that I get for all three sets are very similar (all obtained with the same alignment medium, so no surprise there).
My question is, once XPLOR gets the A and Rh terms, how does it correct for the differences in the magnitudes of the couplings when calculating the energetics and errors? Two of the classes that I used in defining the RDCs had arbitrary names (JNC and JCC). Only JNH is a class that was previously defined in the script. I note that our fits from PALES are much better than what the output of XPLOR suggests they are; so I suspect there is some correction term that I am missing. Thanks, Tom Pochapsky
