"Then I used CNS to do annealing, then use refmac to do rigid body refinement."
That can be why the R-factors went up. Rigid-body subsequent to simulated annealing will (if anything) undo the refinement ... Anastassis Perrakis wrote: > Just to point out that I have missed the NCS presence; Lijun is > *perfectly* correct; even more I should emphasize the point and > say that at 3.0 A, Thou Must Use NCS (if I say again anything about > Gospels and Kleywegt we end up with more facebook groups ...) > >> I think there is no reason at this resolution edge (~3A), making >> bonds possibly resolvable, that NCS should not be used, > >>> By the way, it is a dimer and I didnot use NCS restarin >>> during refinement. Below is from refmac log: > > I would however disagree with Lijun thats its instability. Of course > the 180 cycles are of no use at all > (10 cycles in Refmac are more than enough in 99% of cases), but Rfree > shoots up from 32.6 to 36.2 in 12 cycles, > which is clearly an indication of some sort of pathology, and not > instability. > > Well, tight NCS is the best starting point in this case. > > Tassos > >