Dear Nazia Nasir,
it is important to know what you do BETWEEN the refinement cycles. Rfree
not moving and R1 dropping is often a sign of overfitting, i.e. you
might be adding water molecules into the noise or refine the occupancy
of single atoms, e.g. in a ligand or of the water molecules.
As a general rule, carry out as much model building as possible and run
as few refinement runs (not cycles within a run!!!) as possible.
Best,
Tim
On 12/10/2013 07:51 AM, Nazia Nasir Phd2009,ProteinCrystall.Lab wrote:
> Hi,
>
> I am facing a problem in refining one of my structures. With every
> refinement the Rwork is going down. However, the Rfree is stuck and is
> not going down with refinement. I have already solved the structure
> without the co-factor bound. This structure is with the co-factor
> bound. Can anyone suggest the reason for the Rfree getting stuck?
>
> Thanks
>
--
Dr Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen
GPG Key ID = A46BEE1A
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