Dear Charles, I usually look at the course of CC1/2 (anom) across the resolution bins. It should be high'ish at low resolution and a good resolution cut-off for e.g. shelxd is where it drops below 30%.
The certainly by far best criteria is a traced structure (for a protein, though). With shelx c/d/e that's easy to set up and test. If it cannot be traced, this does not mean there is no useful anomalous signal, but that's also true for all the other indicators - there are structures being solved from anomalous data where the usual indicators indicate hardly any signal at all. E.g. the anomalous data available for 3LDC looks pretty hopeless: Resl. Inf. 7.77 4.78 3.60 2.94 2.52 2.22 1.99 1.81 1.67 <d"/sig> 1.10 0.95 0.84 1.01 0.99 0.95 0.83 0.73 0.71 0.66 yet, shelxd locates three out of 5 K+ ions (with lambda = 0.979A...) within only 100 trials and no special settings. Best, Tim On 09/04/2014 10:05 PM, CPMAS Chen wrote: > Dear All CCP4 users, > > Recently, I have protein crystals cocrytallized with Br-containing ligand. > sometimes, I feel confusion about whether the data have reliable anomalous > information or not. > > Do you guys have some recommendation of the criteria? phenix reported > anomalous measurability, CCP4/aimless has RCRanom. Sometimes, they are not > consistent. > > Thanks! > > Charles > -- Dr Tim Gruene Institut fuer anorganische Chemie Tammannstr. 4 D-37077 Goettingen GPG Key ID = A46BEE1A
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