anomalous completeness from Phenix Xtriage result
Dear All, After check my data with Phenix Xtriage, I got a warning of "the anomalous completeness is 42.34%". I do not know if I need to pay attention to this? I did not do experimental phasing and I did not add heavy metal to my crystal nor there is selenium on my protein. I even don't know why I still get the anomalous signal. But from the detailed summary below I guess in my case it's not a problem? ----------Summary---------- File name: P2_rejoutput.sca Data labels: I(+),SIGI(+),I(-),SIGI(-) Space group: P 1 2 1 Unit cell: 72.255, 46.617, 134.086, 90, 90.052, 90 Data type: xray.intensity Resolution: 49.1682 - 2.5855 Anomalous: True Number of reflections (non-anomalous): 27184 Completeness (non-anomalous): 95.42% Number of reflections (all): 38285 Completeness (all): 69.98% Anomalous completeness: 42.34% Completeness (non-anomalous) is the completeness of the data after merging Friedel pairs. Completeness (all) is the completeness of the data before merging Friedel pairs. Completeness (anomalous) is the completeness of the anomalous data. The anomalous completeness is calcluated by dividing the number of measured acentric, Bijvoet mates by the total possible number of acentric indices. Completeness (non-anomalous) should be used to determine if there is sufficient data for non-anomalous purposes (refinement, model-building). A value greater than 90% is generally desired, while a value less than 75% is considered poor. Values in between will provide less than optimal results. Completeness (anomalous) should be used to determine if there is sufficient data for anomalous purposes (phasing, finding anomalous atoms, refinement of anomalous occupancies or scattering factors). A value greater than 80% is generally desired, while a value less than 50% is considered poor. Values in between will provide less than optimal results. Thanks.
On Jan 21, 2016, at 19:58, Alex Lee
wrote: Dear All,
After check my data with Phenix Xtriage, I got a warning of "the anomalous completeness is 42.34%".
I do not know if I need to pay attention to this? I did not do experimental phasing and I did not add heavy metal to my crystal nor there is selenium on my protein. I even don't know why I still get the anomalous signal.
But from the detailed summary below I guess in my case it's not a problem?
I would not worry about it either, since you do not plan to phase off the anomalous signal, and your non-anomalous completeness is OK. // Johan Research Specialist @ Gonen Lab ____________________________________________________ Janelia Research Campus * 19700 Helix Drive Ashburn, VA 20147 * +1 (571) 209-4000 extension 3376
participants (2)
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Alex Lee
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Hattne, Johan