Re: [ccp4bb] Twinning and R-Free

2017-03-02 Thread Eleanor Dodson
gt; > *Van: *Kay Diederichs > *Verzonden: *woensdag 1 maart 2017 23:38 > *Aan: *CCP4BB@JISCMAIL.AC.UK > *Onderwerp: *Re: [ccp4bb] Twinning and R-Free > > > Hi Alun, > > that's difficult to understand for me. It is my understanding that for an > imperfect model, refmac will i

Re: [ccp4bb] Twinning and R-Free

2017-03-01 Thread Robbie Joosten
Diederichs<mailto:kay.diederi...@uni-konstanz.de> Verzonden: woensdag 1 maart 2017 23:38 Aan: CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@JISCMAIL.AC.UK> Onderwerp: Re: [ccp4bb] Twinning and R-Free Hi Alun, that's difficult to understand for me. It is my understanding that for an imperfect m

Re: [ccp4bb] Twinning and R-Free

2017-03-01 Thread benjamin bax
Hi Alun, 1. What does phenix.xtriage think of the dataset? 2. What kind of redundancy do you have in the dataset? 3. Sometimes with a large crystal and a small beam the twin fraction varies as you rotate the crystal and illuminate different parts of the crystal (which can have different twin fra

Re: [ccp4bb] Twinning and R-Free

2017-03-01 Thread Kay Diederichs
Hi Alun, that's difficult to understand for me. It is my understanding that for an imperfect model, refmac will indicate a twin fraction >0 even if in reality it is 0. But alpha=0.372 sounds too high for that. My questions would be - a) is it a single dataset, or did you merge ? If the latter, i

[ccp4bb] Twinning and R-Free

2017-03-01 Thread Alun R Coker
Hi Everyone, I have a (2.5 - 2.3 Angstroms) data set the process as I4 or I222. Aimless indicates twinning in both space groups and all the lower symmetry space groups consistent with the reduced cell. Molecular replacement works in I4 but not I222 etc. I can see new density for a ligand we a