<d"/sig> should be above 0.80 There seems to be plenty of signal there with all values above 1.02. We have solved structures with less multiplicity and lower <d"/sig>.
There is a different criteria of "signal" for when you know the positions of the anomalous substructure atoms and when you need to find the positions of the anomalous substructure atoms. As for "no signal", I think I am on record that there is always an anomalous signal. :) But can you detect it? Jim ________________________________ From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Faisal Tarique [faisaltari...@gmail.com] Sent: Friday, April 25, 2014 4:06 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] anomalous signal Dear all sorry about my previous mail where i forgot to mention that the data was collected on home source at Cuk alpha and at 1.54A. written below is the log file of an anomalous data processed through SHELXC..my question is ..what is the strength of anomalous signal ?? as it is said "For zero signal <d'/sig> and <d"/sig> should be about 0.80". Then in the present case is there really a signal or can be assumed no signal..we are expecting one Ca atom bound to the protein at its active site..the redundancy of the data is 11.6..with this signal strength can we assume Ca to be present there or whatever little anomalous if present is due to something else....or there is no signal at all ??... Resl. Inf - 8.0 - 6.0 - 5.0 - 4.0 - 3.8 - 3.6 - 3.4 - 3.2 - 3.0 - 2.8 - 2.60 N(data) 375 493 580 1319 450 538 679 866 1081 1414 1709 <I/sig> 58.8 38.6 32.6 38.3 27.7 27.2 21.9 18.4 12.6 9.5 6.1 %Complete 94.7 99.0 99.3 99.5 100.0 99.6 99.7 99.8 99.6 99.6 90.9 <d"/sig> 1.65 1.27 1.18 1.25 1.19 1.12 1.11 1.11 0.97 1.02 1.05 -- Regards Faisal School of Life Sciences JNU
