typo correction, you'll want the long axis parallel to the rotation
axis, not to the beam.
Mark
Quoting Frank von Delft:
> You probably have to tilt your crystal, so that the long axis is
> parallel to the beam. We do this routinely: cut a plastic pipette
> tip to have a sharp point, then push the loop where it attaches to
> the pin, to bend the crystal itself.
>
> You have to identify from your diffraction whether the long axis is
> pointing through the face or the edge of the loop. As it's P6,
> chances are it's through the face, because long-axis P6 tends to
> make flat hexagons which lie flush with the face. So you have to
> bend so the face of the loop upwards.
>
> You'll have to practice this first, though, so put up an empty loop.
> Top tips:
> * Don't breathe! You'll blow the cryostream away.
> * Bend the loop towards (rather than away from) the rim edge of
> the pin to which it's glued.
> * Don't breathe!
> * Practise practise practise.
>
>
> Another thing: most in-house sources allow you to reduce divergence
> of the beam. You lose intensity, but no matter, just expose longer.
> That also improves overlap.
>
> Cheers
> phx
>
>
>
> On 07/03/2012 04:56, Dipankar Manna wrote:
>>
>> Dear Crystallographers,
>>
>> I am working on a protein having SG P6, the cell parameters are a=
>> 79, b= 79, c= 325. The crystals are forming in big size and with
>> very good shape. It also diffracting very well in Home source
>> facility both in terms of resolution and intensity. But the only
>> problem is the number of overlaps. Its showing much more than the
>> good spots. As a result the completeness is showing maximum up to
>> 65% even after collecting 180 degrees. I am unable to get a
>> complete data. I tried with reducing the oscillation angel to 0.3
>> degree/0.5 degree but it did not improve that much. Please give me
>> some suggestions.
>>
>> Regards,
>>
>> Dipankar
>>
>> /Dipankar Manna/
>>
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Mark J van Raaij
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Dpto de Estructura de Macromoléculas
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