Maia,

provided radiation damage is not a major detrimental factor, your data are just fine, and useful also in the high resolution shell (which still has <I/sigma> of 2.84 so you could probably process a bit beyond 2.25A).

There is nothing wrong with R_meas of 147.1% since, as others have said, R_meas is not limited to 59% (or similar) as a refinement R-factor is. Rather, R_meas is computed from a formula that has a denominator which in the asymptotic limit (noise) approaches zero - because there will be (almost) as many negative observations as positive ones! (The numerator however does not go to zero)

Concerning radiation damage: First, take a look at your frames - but make sure you have the same crystal orientation, as anisotropy may mask radiation damage! Then, you can check (using CCP4's loggraph) the R_d plot provided by XDSSTAT (for a single dataset; works best for high-symmetry spacegroups), and you should also check ISa (printed in CORRECT.LP and XSCALE.LP).

HTH,

Kay

P.S. I see one potential problem: "XSCALE (VERSION December 6, 2007)" when the calculation was done 28-Aug-2009. There were quite a number of improvements in XDS/XSCALE since that version. The reason may be that a licensed, non-expiring version was used - make sure you always rather use the latest version available!


> -------- Original Message --------
> Subject: [Fwd: Re: [ccp4bb] I/sigmaI of >3.0 rule]
> Date: Thu, 3 Mar 2011 10:45:03 -0700
> From: Maia Cherney <[email protected]>
>
>
>
> -------- Original Message --------
> Subject: Re: [ccp4bb] I/sigmaI of >3.0 rule
> Date: Thu, 03 Mar 2011 10:43:23 -0700
> From: Maia Cherney <[email protected]>
> To: Oganesyan, Vaheh <[email protected]>
> References: <[email protected]>
> <[email protected]>
> <[email protected]>
> <[email protected]> <[email protected]>
> <[email protected]>
>
>
>
> Vaheh,
>
> The problem was with Rmerg. As you can see at I/sigma=2.84, the Rmerge
> (R-factor) was 143%. I am asking this question because B. Rupp wrote
> "However, there is a simple relation between <I/sigI> and R-merge
> (provided no other indecency has been done to the data). It simply is
> (BMC) Rm=0.8/<I/sigI>."
> Maybe my data are indecent? This is the whole LP file.
>
> Maia
>
> MMC741_scale-2.25.LP
>
>
>******************************************************************************
>                    XSCALE (VERSION  December 6, 2007)      28-Aug-2009
>******************************************************************************
>
> Author: Wolfgang Kabsch
> Copy licensed until (unlimited) to
>  Canadian Light Source, Saskatoon, Canada.
> No redistribution.
>

--
Kay Diederichs                http://strucbio.biologie.uni-konstanz.de
email: [email protected]    Tel +49 7531 88 4049 Fax 3183
Fachbereich Biologie, Universität Konstanz, Box M647, D-78457 Konstanz

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