From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of SD
Y
Sent: Sunday, November 04, 2012 4:04 PM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] low-resolution data and SG
Dear All,
I have few basic questions for which I need help. I have a 3.4 A
data and I

There are several questions here.
1) What is the point Group - P4 or P422.
I find the pointless statistics which check all symmetry operators singly
useful. If the 2 fold kh-l gives about the same CC as the 4 fold operators k-hl
-h -k l -k h l then you probably do have point group P422. ( But

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Dear SDY,
if you can see extra density after MR into which you can even build or
correct the model it is a good sign your chose the correct space group.
Check the geometry of your model. I suppose it is very distorted - a
matrix weight of 0.03

This looks like an output from SCALEPACK. Unfortunately, one has no way to
know from the output if 21 and 90 are strong intensities or not. One cannot go
by the I/sigmaI alone. For example, suppose there is thermal diffuse scatter
at these positions or perhaps there is a cosmic ray or