Dear all,
I recall that the set of Rfree reflections should be 500-1000, rather than
5-10%, but I cannot find the reference for it (maybe Ian Tickle?).
I would therefore like to be confirmed or corrected:
Is there an absolute number required for Rfree to be significant, i.e. 500-1000
board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of
Tim Gruene
Sent: Tuesday, March 26, 2013 09:33
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Rfree reflections
Dear all,
I recall that the set of Rfree reflections should be 500-1000, rather than
5-
10%, but I cannot find the reference
Of
Tim Gruene
Sent: Tuesday, March 26, 2013 09:33
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] Rfree reflections
Dear all,
I recall that the set of Rfree reflections should be 500-1000, rather than
5-
10%, but I cannot find the reference for it (maybe Ian Tickle?).
I would
board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of
Tim Gruene
Sent: Tuesday, March 26, 2013 11:05
To: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] Rfree reflections
Hi Robbie,
thank you for the explanation. Heinz Gut and Michael Hadders pointed me at
Axel Brunger's publication Methods
...@hotmail.com
Date:
To: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] Rfree reflections
Hi Tim,
The derivation of sigma(Rw-free) is in this paper: Acta Cryst. (2000). D56,
442-450. Tickle et al.
Note the difference between the sigma of weighted/generalized/Hamilton
R-free
From: Robbie Joosten robbie_joos...@hotmail.com
Date:
To: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] Rfree reflections
Hi Tim,
The derivation of sigma(Rw-free) is in this paper: Acta Cryst. (2000). D56,
442-450. Tickle et al.
Note the difference between the sigma
Tim,
r-free flags are used to calculate maximum-likelihood parameters (sigmaa,
or alpha/beta - depending on parameterization), as well as m and D in
2mFo-DFc and mFo-DFc maps. For this they are supposed to be evenly
distributed across resolution range, and the number of flags per thin
enough
