[phenixbb] R/ R free (overall) and R/Rfree (for highest resolution shell)

[Pavel Afonine]

George,

what exactly you are trying to achieve by making sense of Rfree and its 
relation to Rwork in resolution shells? Just curious..

Pavel

On 1/26/15 1:50 PM, George Devaniranjan wrote:
> Thank you Tim and Pavel.
>
> Sorry, just to follow up:
>
> For the example I gave R /Rfree difference seems high. Can this still 
> be down to statistical fluctuations?
>
> I am just trying to get a feel when we can simply put it down to 
> statistical fluctuations and when its a concern.
>
>
> On Mon, Jan 26, 2015 at 4:26 PM, Tim Gruene <tg at shelx.uni-ac.gwdg.de 
> <mailto:tg at shelx.uni-ac.gwdg.de>> wrote:
>
>     Dear George,
>
>     you may also want to take into account that the variation of Rfree is
>     estimated as Rfree^2/k, where k is the number of reflections in the
>     shell. If you only have e.g. 100 reflections there, this might
>     simply a
>     statistical fluctuation, as far as I understand.
>
>     Cheers,
>     Tim
>
>     On 01/26/2015 10:05 PM, George Devaniranjan wrote:
>     > Hi,
>     >
>     > I calculated/validated several PDB structures in
>     Phenix.Validation (GUI)
>     >
>     > The R/R-free (overall) is
>     >
>     > 0.1271/0.1348
>     >
>     > Further down I looked at the R/R-free for the highest resolution
>     shell.
>     >
>     > Its 0.2538/0.2446
>     >
>     > I am curious why the R-free for the *highest resolution shell*
>     seems to be
>     > LOWER than R (work).
>     >
>     >
>     > Am I reading the information wrong?
>     >
>     > PDB: 3QL9
>     >
>     > Thank you,
>     > George
>     >
>     >
>     >
>     > _______________________________________________
>     > phenixbb mailing list
>     > phenixbb at phenix-online.org <mailto:phenixbb at phenix-online.org>
>     > http://phenix-online.org/mailman/listinfo/phenixbb
>     >
>
>     --
>     Dr Tim Gruene
>     Institut fuer anorganische Chemie
>     Tammannstr. 4
>     D-37077 Goettingen
>
>     GPG Key ID = A46BEE1A
>
>
>     _______________________________________________
>     phenixbb mailing list
>     phenixbb at phenix-online.org <mailto:phenixbb at phenix-online.org>
>     http://phenix-online.org/mailman/listinfo/phenixbb
>
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://phenix-online.org/pipermail/phenixbb/attachments/20150126/0df0c943/attachment.htm>