This point group can be four fold twinned so it is possible but unlikely
that you have equal degrees of twinning along all possible twinning axes.
More likely that you have the space group wrong.
Did you test all possibilities; PG321 PG 312 PG 6 PG 622 (all this is
very easily tested with p
Hi, Peter,
I have tried to carry out MR in P3. It turned out that P31 is the right one.
After MR, I refined it
using Phenix.refine with or without twin law. The result is as following:
Twin law R Rfree
Twin fraction in phenix.refine
None
People dont read the CCP4 documentation on twinning! Grrr
PG P3 can have 3 twinning operators; and these are:
k,h,-l ( or symm equiv) - if this is a crystallographic operator the
PG becomes P321
-h,-k,l (or symm equiv) - if this is a crystallographic operator the PG
becomes P6
-k,-h,-l (or sy
Hi,
I tried to processed it as P321. It seemed that it might be right. The
Rmerge increased
just a little. Then I used phenix.xtriage and sfcheck to check it. The
results are as following:
phenix.xtriage:
Twinning and intensity statistics summary (acentric data):
Statistics independent of twin
I cant follow this very well.
Try SFCHECK as well which will do the same tests and give a differently
formatted output..
or TRUNCATE which gives you plots of these stats v resolution..
/^2 : 2.351 This is higher than the expected value of 2 for untwinned data.
(1.5 for perfectly twinned data
Dear guys,
I have collected a dataset with the sg as P31. I ran pehnix.xtriage to
analyse the data with
following result:
Twinning and intensity statistics summary (acentric data):
Statistics independent of twin laws
- /^2 : 2.351
- ^2/ : 0.788
- <|E^2-1|> : 0.766
- <|L|>, : 0.446, 0.2
