[ccp4bb] Is the Rmerge invalidate by twinned data?

2010-10-06 Thread fulvio saccoccia
Dear all, I have a data set collected at 3A resolution. I processed the data but I had to cut the resolution at 3.6A for the high value of Rmerge (at 3.6A it is 0.18). After scaling and MR I realized that my data were twinned. This is my question: can I reprocess all the data set using all

Re: [ccp4bb] Is the Rmerge invalidate by twinned data?

2010-10-06 Thread Ed Pozharski
You don't need twinning to invalidate the Rmerge as a criterion for the resolution cutoff, there are other reasons why you should use I/sigma instead. If you process data all the way to 3A, what's the I/sigma in the highest resolution shell? On Wed, 2010-10-06 at 11:28 +0200, fulvio saccoccia

Re: [ccp4bb] Is the Rmerge invalidate by twinned data?

2010-10-06 Thread Jim Pflugrath
It may be time for our annual I/sigmaI discussion. Please note that I/sigmaI is what the RCSB expects from you and it is generally lower than I/sigmaI. Some packages do not output I/sigmaI in an obvious place for you to put in your Table 1. :) On Wed, 6 Oct 2010, Ed Pozharski wrote: You

Re: [ccp4bb] Is the Rmerge invalidate by twinned data?

2010-10-06 Thread Jon Schuermann
Fulvio, We need more info to give advice. First, when you say Rsym is 0.18, are you talking about in the high res bin or overall? Second, how did you determine you have twinning? In what space group did you scale your data? If your data is actually twinned with a high twin fraction, and