Hello Yafang, The answer lies in the fact that you used HKL2000. Scalepack has a long standing "feature" where it reports Rmerge > 100% as zero. Quite why they do that is a mystery, but your Rmerge in the outermost shell is NOT zero - the Rmerge for the lower resolution shells will show up as non-zero if Rmerge < 100%.
That feature is overdue for a fix. Alternatively export your scaled data with NO MERGE ORIGINAL INDEX and import into CCP4 via Pointless and have Scala or Aimless report the correct statistics. Reprocessing the data using XDS or Mosflm will ultimately lead you to scaling the data with a program that doesn't have that bug. If you do this, report Rmeas rather than Rmerge, the former being a better measure. Phil Jeffrey Princeton ________________________________ From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Yafang Chen [yafangche...@gmail.com] Sent: Wednesday, August 14, 2013 11:32 AM To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Rmerge of the last shell is zero Dear All, Here are some more details about the question I asked earlier about "Rmerge is 0 in the last shell". I processed the data using HKL2000. The space group is I213. Redundancy is 10.2 (10.3). I/sigma is 34.8 (2.3). Rmerge is 6.5 (0.0). Since I/sigmaI is more than 2 in the last shell, I preferred not to cut back the resolution any more. But I don't know how to explain Rmerge in the last shell being 0. Besides, I am wondering if this data is publishable (with Rmerge being 0 in the last shell). Thank you so much for your help! Best, Yafang On Wed, Aug 14, 2013 at 10:59 AM, Yafang Chen <yafangche...@gmail.com<mailto:yafangche...@gmail.com>> wrote: Dear All, I recently processed a dataset, in which I/sigmaI of the last shell is 2.3, while Rmerge of the last shell is 0. Does anyone know why the Rmerge is 0? The completeness is 100 (100). Thank you so much for your help in advance! Best, Yafang -- Yafang Chen Graduate Research Assistant Mesecar Lab Department of Biological Sciences Purdue University Hockmeyer Hall of Structural Biology 240 S. Martin Jischke Drive West Lafayette, IN 47907 -- Yafang Chen Graduate Research Assistant Mesecar Lab Department of Biological Sciences Purdue University Hockmeyer Hall of Structural Biology 240 S. Martin Jischke Drive West Lafayette, IN 47907