Dear TO,
at medium to poor resolution, I prefer to set the weighting myself rather than
use the automatic weighting. At 3'ish A resolution, I would start with 0.01 or
0.005 with many more than the default 10 cycles, maybe 50 or 100. The numbers
you list below go in the other direction (>4).
mentioned - the actual delta values are context
> dependent.
> Best, BR
> From: CCP4 bulletin board On Behalf Of Andrew Leslie
> Sent: Friday, March 6, 2020 08:52
> To: CCP4BB@JISCMAIL.AC.UK
> Subject: Re: [ccp4bb] Overrefinement considerations and Refmac5.
> I would like
I would like to add a small caveat to Eleanor’s rule about a 3% difference
being too low for a structure refined against 3Å data.
If the 3Å data is for a structure that has already been solved at much higher
resolution (e.g. 2Å) and the only difference for the 3Å dataset is a different
ligand
Dear Eleanor, dear Michel (?),
A while ago we statistically analysed the distribution of R, Rfree and of their
difference as a function of the logarithm of resolution (Urzhumtsev et al.,
2009, Acta Cryst, D65, 1283-1291).
In this log-scale, the mode values for all three are nearly linear
You dont give the data resolution - that is very important..
I hate this rule bound approach to Rfree - R differences.. but as a guide
No non-crystallographic symmetry.
1A data - you would expect them to be almost equal
3A data - I would expect a difference of at least 10% - once had the
pleasure
Dear BBers,
I am trying to refine a structure using COOT and Refmac5 and I have some
concerns about overrefinement and x-ray term weight in Refmac5, based on
the fact that during refinement to let R factor to drift too far from Rfree
is not good...
So... First question about that : what is too
