Hi Harry,

You’re not wrong - “conventional wisdom” these days is pointing to CC of about 
0.3 but I suspect that the difference is pretty modest in general

However, in the case, the difference could have an impact as the higher 
resolution reflections may have something to say about the overall B factors

I also wondered about the order of the data collection in this case, since 
there will probably be a certain amount of radiation damage across this number 
of data sets at non-cryo temperatures

Best wishes Graeme

> On 8 Sep 2022, at 10:21, Harry Powell 
> <[email protected]> wrote:
> 
> hi folks
> 
> I’ve been away from data processing for a while, but am I alone in thinking 
> that scaling to ~0.6 CC 1/2 cutoff might be ignoring a lot of useful data? I 
> seem to remember that AutoProc and xia2.multiplex use a default of >= 0.3.
> 
> Harry
> 
>> On 7 Sep 2022, at 19:46, Matt McLeod <[email protected]> wrote:
>> 
>> Hi everyone,
>> 
>> I have a series of datasets at 253K (~2.0A), 273K (2.0A), 293K (2.0A), 313K 
>> (2.2A) and I am curious as to the details in determining B-factors.
>> 
>> I have treated these datasets more-or-less identically for comparison's 
>> sake.  I used DIALS to index, integrate, and scale the data.  I scaled the 
>> data to a ~0.6 CC1/2 cutoff.  
>> 
>> After fully refining the datasets, there is an odd trend with respect to 
>> temperature (from what has been previously published) and I assume that this 
>> is because of "behind-the-scenes" computation rather than a biophysical 
>> observation.  The B-factors slightly decrease from 252-293K, and then 
>> significantly drop at 313K.  The maps look pretty well identical across the 
>> datasets.
>> 
>> 253K - 53.8 A^2
>> 273K - 48.4 A^2
>> 293K - 45.5 A^2
>> 313K - 18.6 A^2
>> 
>> I compared the wilson intensity plots from DIALS scaling for 273K and 313K 
>> and they are very comparable.
>> 
>> I am looking for suggestions as to where to look at how these b-factors are 
>> selected or how to validate that these B-factor are or are not accurate.  
>> Also, any relevant literature would be welcomed.  From what I have read, 
>> there is a general trend that as T increase, the atoms have more thermal 
>> energy which raises the b-factors and this trend is universal when comparing 
>> datasets from different temperatures.
>> 
>> Thank you and happy to supply more information if that is helpful,
>> Matt
>> 
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