I agree. Large crystals often diffract more poorly than smaller ones.
I would hazard a guess that large crystals may experience more
mechanical distortion during flash cooling, but it's just a guess. In
our lab, the sweet spot for most of our crystals is 0.3-0.4 mm. Larger
is usually worse, and smaller has weaker scattering.
Cheers, Roger Rowlett
On 4/14/10, W H <[log in to unmask]> wrote:
> 50% solvent content in a small crystal is still 50% solvent content in
> a large crystal given the same crystal form, so it's tough to use that
> to explain loss of diffraction.
>
> Very large crystals in my hands seem to suffer from more problems of
> mechanical stress.
>
>
>
> William
>
>
> On Wed, Apr 14, 2010 at 5:36 PM, syed ibrahim <[log in to unmask]>
> wrote:
>> Hi All
>>
>> I had two crystals grown in same well, one is small and other is 10 times
>> bigger. I treated both crystal in same cryo and same time. The smaller one
>> diffracted to 2.5A and the bigger one to 6-7A. I was expecting the bigger
>> one to diffract high resolution.
>>
>> I assume the bigger crystal might have lot of solvent which prevent for
>> high resolution. If it is true what could be the best way to dehydrate
>> crystal without affecting crystal quality?
>>
>> Thank you
>>
>> Syed
>>
>> PS: Taken care of less solvent to be present in the loop
>>
>>
>>
>>
>
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