On Fri, Oct 14, 2011 at 7:34 PM, Ed Pozharski
<[log in to unmask]> wrote:
On Fri, 2011-10-14 at 23:41 +0100, Phil Evans wrote:
> I just tried refining a "finished" structure turning off the FreeR
> set, in Refmac, and I have to say I can barely see any difference
> between the two sets of coordinates.
The amplitude of the shift, I presume, depends on the resolution and
data quality. With a very good 1.2A dataset refined with anisotropic
B-factors to R~14% what I see is ~0.005A rms shift. Which is not much,
however the reported ML DPI is ~0.02A, so perhaps the effect is not that
small compared to the precision of the model.
On the other hand, the more "normal" example at 1.7A (and very good data
refining down to R~15%) shows ~0.03A general variation with a variable
test set. Again, not much, but the ML DPI in this case is ~0.06A -
comparable to the variation induced by the choice of the test set.
Cheers,
Ed.
--
Hurry up, before we all come back to our senses!
Julian, King of Lemurs