Hi all, I have been refining twinned data (at 3.1 A resolution) using refmac. My R and Rfree values are 19.6 and 26.2 respectively with NCS restraints and isotropic B-factor refinement.. I am not sure weather it is a good idea to refine individual B-factors at this resolution.
I have also tried refining the same model in phenix but this time not refining the Bfactors. My Rfactor and Rfree are 25 and 32 respectively. Refining with TLS in Phenix drops R factors to 23 and 29. Then I used the output PDB from phenix and refined it in CCP4 (selecting overall B-factor refinement option instead of Isotropic) and my R factors are R work=16 and Rfree =21. If Rfree reflections are refined my refmac upon switching from phenix to refmac then does this contaminate the Rfree set ? Should swiching between refinement programs Phenix and Refmac be avoided? Urmi Dhagat
