The R factors may be high because the structure is imperfect - almost inevitable at that resolution - but also there are often serious difficulties with scaling at this resolution . If you are using REFMAC look at the <Fo> v <Fc> wrt resolution plot at the end of refinement (follows R and Rfree plot v resolution 0. You may see there is a large discrepancy.. Never sure what to do about it - the higher resolution data you can use the more reliable the scaling so maybe you can extend the resolution by accepting CC1/2 < 0.5 or whatever your data cut off is based on.. REFMAC offers various scaling options, trying to deal with the bulk solvent.
But maybe your scaling is OK - just check it as a matter of course!1 Eleanor On 14 June 2017 at 15:32, Matthias Barone <[email protected]> wrote: > If you dont use Phenix, print the figures of > https://doi.org/10.1016/S0969-2126(02)00743-8 > and use them beside your screen. Helps a lot if you wanna have a quick > look at Rfact distributions.. > > > >>> Paul Emsley <[email protected]> 14.06.17 15.25 Uhr >>> > On 14/06/2017 14:09, Khoa Pham wrote: > > Dear CCP4 members, > > > > I am refining a structure with a resolution of ~ 2.9 A and the > Rwork/Rfree are are > > 0.34/0.37, respectively. > > My question is that these Rwork/Rfree are acceptable for publication. > > If you have Phenix, try POLYGON. That will give you a good clue. > > >If not, how can I > > reduce them? > > > > That is more complicated to answer. > > > Paul. >
