Well - you can hardly get a higher symmetry space group to match some of
the NC related molecules!
Good luck with the number 6.
This isnt any real help but I cant solve a ferritin structure in SG I432
- it probably forms a cage like the other feritins around the origin,
but every solution I get clashes with others..
After listening to a lecture by a small molecule crystallographer I
wondered whether there isnt some crystal defect but I am not sure how to
monitor it..
Eleanor
Yanming Zhang wrote:
> Sorry I forget to tell ya the details:
>
> The SG of my Data is cubic P4332. Cell is 251.34A in all three
> dimensions.
> Resolution is 3.1A. 5,6,7,8 might be the possible copies from Matthew
> coeficient. But I just trust 6 because Chinese like the number 6
> (happy Chinese new year by the way :)). No pseudo translation judged
> by Native Patterson. Self-rotation at the section kappa=180 shows
> strong peaks at phi=45 and psi=45.At the stage of map generation, the
> Rfree is 42% R is 38%.
> Thanks!
> Yanming
>
>
> On Tue, 13 Feb 2007, Eleanor Dodson wrote:
>
>> Sometimes this sort of disorder is due to an error , so the first
>> thing is to check very carefully that the solution makes sense.
>>
>> Why are you so sure there are 6 copies in the asymmetric unit?
>>
>> In situations like this I first worry about SG.
>>
>> Is there a pseudo-translation vector? This can make it hard to decide
>> on the SG..
>>
>> Is there an alternate spacegroup with fewer molecules in the asymm unit?
>>
>> What does the self rotation show?
>>
>>
>>
>> Yanming Zhang wrote:
>>> Dear All,
>>>
>>> Maybe this is a trivial question:
>>>
>>> My data should have 6 molecules in one assymetric unit. MR could
>>> find out 4 molecules. After this, no matter how hard I have tried,
>>> no more molecules can be found. At this stage, I suppose that all
>>> other copies are dis-ordered. And go ahead to do refinement with 4
>>> molecules (ABCD) available.
>>> The density for A is quite good. But for BCD are very dis-ordered.
>>> Many breaks in chains. I'd like to ask you:
>>> In a situation like this, should I:
>>> A, Use NCS for all copies?
>>> B Do not use NCS at all?
>>> C, Use NCS just for BCD? (even dis-ordered, but similar)?
>>> What is the trick to lower down Rfree as soon as possible, if you
>>> have experienced the same situation before?
>>>
>>>
>>> Thanks
>>>
>>> Yanming
>>>
>>>
>>
>>
>
>
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