Re: [ccp4bb]: Twinning/Merging

[Jim Pflugrath <jwp@msc.com>]

***  For details on how to be removed from this list visit the  ***
***    CCP4 home page http://www.dl.ac.uk/CCP/CCP4/main.html    ***



On Fri, 15 Dec 2000, Jim Pflugrath wrote:

> [... snip ...]
> > ... For weak crystals, collected with in-house 
> > instrumentation, 16% Rmerge is not uncommon. Best of all, tons of 
> 
> I disagree.  One should be able to expose longer in-house to get the
> required counting statistics, so that Rmerge is lower.

What I wrote applies to in-house cryo-cooled crystals.  With RT data
collection, radiation damage can be a serious problem that is not easily
corrected by current data massaging programs.  After all, the contents of
the unit cell changes during the course of the experiment due to radiation
damage.