As far as I know all the programs we use will handle the non-primitive hexagonal setting of rhombohedral space groups (ie a=b != c, alpha=beta=90, gamma =120), often denoted "H3" or "H32" (aka R3:H in cctbx). Many of them will probably handle the primitive rhombohedral setting (a=b=c, alpha=beta=gamma), but this is much less commonly used in macromolecular crystallography, so some programs may fail to do the right thing (though they should). A space group denoted "R3" or "R32" may be in either setting, depending on the cell dimensions. I don't know what HKL2000 does, but "H32" is not primitive, it is the centred hexagonal setting.
The paper cited by Ivan presumably used the hexagonal setting, since they had c != a or b
confusing I know
Phil
On 12 Aug 2010, at 00:42, xaravich ivan wrote:
> Hello Ray,
> You can contact the author of this paper. It seems they used denzo scalpack for R32.
> Ivan
>
> On Wed, Aug 11, 2010 at 8:53 AM, Eleanor Dodson <[log in to unmask]> wrote:
> If you cant import a file with symmetry labelled R32 but with a=b and alpha=beta = 90, and gamma = 120 then something is wrong - the symmetry checking looks at both name and cell.. or at least it used to..
>
> The output mtz would have symmetry name changed to H32, but that is just a name - in each case the sym ops and cell should be h32 style..
> Eleanor
>
>
>
>
> Ray Brown wrote:
> Hi, I have read all of the past messages about the confusion of H32 and R32 and I want to get the correct indexing sp that I can import the .sca file into CCP4..
>
> I use DENZO and SCALEPACK in HKL2000. If you read the manual then it states that space group R32 should only be autoindexed by DENZO on a primitive lattice using the DENZO keyword H32. This indeed gives a primitive unit cell and not the hexagonal setting apparently demanded by CCP4 programs.
>
> What do you do next? It is possible in SCALEPACK to reindex the H32 primitive data into a rhombohedral hexagonal setting which SCALEPACK calls R32. Or course you cannot import this .sca file into CCP4. Why not?
> I can go into the .sca file and edit the header and change the R32 label to H32. Does this screw up the indexing?
>
> If anybody has successfully used DENZO/SCALEPACK/CCP4 in space group R32 then please tell me how to do it correctly.
>
> Cheers.
>
> Ray
> email [log in to unmask]
>
> <am0110-1.pdf>
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