Dear Crystallographers,
There have been comprehensive discussions on the use of criteria such
as Rmerge and I/sigma(I) as criteria to define the resolution to which
X-ray data is to be used for structure determination. However, CC 1/2,
the correlation between random half sets of data, is increasingly being
considered as a better means for evaluating the resolution cutoff
(Karplus and Diederichs). Is there a resolution cutoff that can be
considered as a acceptable standard, say CC 1/2 = 0.5, or does this
prompt the counter-question 'how long is a piece of string?' in which
case resolution values are to be quoted at CC 1/2 values of 0.2, 0.3,
0.5, 1, etc?
Best wishes,
Michael
Michael Roberts
Crysalin Limited
Cherwell Innovation Centre
77 Heyford Park
Upper Hey ford
Oxfordshire OX25 5HD
|