There is a lot of confusion about this!
You can call it R3:H ( indexed with a=b and gamma = 120)
This is also called H 3 in the PDB deposition and the CCP4 symmetry
libraries.
(But for the CCP4 library - it checks the axes and angles to decide
whether this is using the H ( or hexagonal) convention..)
The name R3:R or R3 is usually used for indexing where a=b=c, and
alpha=beta=gamma.
However both conventions describe the same diffraction. pointless or
othercell ( from the CCP4 prereleae) will give you the reindexing
transformations to change from one convention to the other.
It is usually easier to visualise a protein molecule in the H3
convention but not always..
Eleanor
linwoo kang wrote:
Dear all
Recently I collected a dataset, which is rhombohedral on indexing
screen of HKL2000.
I processed the dataset as R3 and R32 at synchrotron.
But I realized it can be H3 or H32. Is it correct?
Cell dimensions are a=b >< c and alpha=90, beta=90, and gamma=120.
For me, synchrotron is only place to index and scale data.
Can I just change space group at CCP4i from sca file processed by R3
into H3 space group or so?
Because cell dimensions are same, maybe indexing can be same.
Accordingly just scaling can be enough for changing space groups but I
am still concerned about completeness and rejected spots, which can be
different at different space groups.
Please advise me! Thanks.
