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[ccp4bb]: p61 vs p65 flipped



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Apologies for the not strictly CCP4 question...

I'm trying to find Se sites in MAD data from crystals of space group p61 or
p65. I was under the impression that the Patterson maps should be the same
for both and that I therefore only needed to solve the Pattersons once.
Experimental Patterson maps from peak data look the same for both. However,
Solve is giving me different solutions for p61 compared with p65.

Also, can anybody out there tell me whether there are 4 different phasing
possibilities: p61 with sites flipped or unflipped, and p65 flipped,
unflipped. Or are 2 pairs of these equivalent? I made 4 maps using all 4
possibilities and they seem to be different but I'm not sure that I've done
everything correctly. For flipped maps I have simply made the Se positions
negative in mlphare (i.e. Se site at 0.1 0.1 0.1 becomes -0.1 -0.1 -0.1),
and made fft maps for all 4.

So, do I need to solve one or two Pattersons, and do I then have 2 or 4
possibilities for phasing?

Any help much appreciated.

Thanks,
Ed
---------
T.Edwards
Mt Sinai Medical School
212 659 8667 office
917 825 6924 cell
212 849 2456 FAX