Depending on your data quality and the nature of the crystal it might be
that you cannot reduce R/Rfree any further.
Low R/Rfree is not the goal of refinement and model building - at least
not for the humans doing it. The goal is to get as good a model as
possible, and if your data are not very good, or also for various other
possibilities you might not be able to improve the statistical guidelines.
I am not suggesting you should stop refining now - but without knowing you
data/ resolution/ data statistics it is very difficult to give an answer.
Cheers, Tim
--
Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen
GPG Key ID = A46BEE1A
On Mon, 7 Jan 2008, Yongchao Li wrote:
I have a large molecule to refine.There are about three thousand residues in
one asymmetric unit.
Except for the lack of electron densities in several places, where the
loops have been deleted, the rest parts fits well with density. But the R free
and R work are all beyond 0.30 (R free = 0.35, R work = 0.30).
I don't know how to reduce them.
Can anyone give me some ideas?
Thank you!
---------------------------------
Looking for last minute shopping deals? Find them fast with Yahoo! Search.
