it depends a bit on what the reason for the data getting “bad” is. - if it’s radiation damage, you may need to collect with less intense x-rays or take shorter images. Merging isomorphous datasets may also help, but this is not always straightforward, for example because different crystals may have reacted differently to freezing. - if the crystal diffracts anisomorphically, i.e. worse in some directions than others, than it may be difficult in any case. You may just have to try and grow better crystals. - as the c-axis is much longer than the other two, you may be able to get data with less overlaps by making sure your crystal rotation axis is roughly along c. You’ll need to figure out where c is with regards to your crystal morphology and then mount the crystal in the correct way (a kappa goniometer, or ever better, a 4-circle goniometer, will help; if the long axis is along the short axis of your crystals, which is observed often, you may need to use bent loops).
Mark J van Raaij Dpto de Estructura de Macromoleculas Centro Nacional de Biotecnologia - CSIC calle Darwin 3 E-28049 Madrid, Spain tel. (+34) 91 585 4616 http://wwwuser.cnb.csic.es/~mjvanraaij > On 8 Nov 2016, at 13:45, 张士军 <21620150150...@stu.xmu.edu.cn> wrote: > > Hi ccp4 guys > > I have a crystal whose spacegroup is I4,and the cell dimension are > a=b=83，while ,the C axis is 315.SO the diffraction data is very bad when the > crystal started to rotate to some degree ,and it is difficult to process the > data .So I wondering there any strategy to resolve this kind of situation ,or > any software to merge different crystal data together to process or phasing ? > thanks a lot for your suggestions !!! > > > Best Regards > > > SHIJUN >
