Respected Madam, > Yes - that is true. > > Any crystal might be split, and give diffraction with overlapping >lattices- ie show non-merohedral twinning. If you are lucky/careful you >might only get a few spots which overlap after integration of one of the >lattices- not enough to be detected as "twinning" from the statistical >analysis... > > but the SG R3 is a classic one for merohedral twinning with operator k,h,-l > > Have you looked at the scala log file - you need to check the L test for >twinning, whether there is non-crystallographic translation etc.. as well >as looking at the moment plots.
I have checked for twinning in L test and H-test both of which indicated slight twinning. I am attached H-test and L-test graph herewith. Sfcheck also indicated 21.2% of pseudotranslation along 0.667 0.333 0.000. But MR using phaser gave a dimer in asu which are related by a 2 fold, so there was no indication of any pseudo translation and protein is bound to 10-12 cadmiums. Could this off origin peak be due to the presence of the heavy atoms? how can i rule out the presence of this pseudotranslation as indicated in sfcheck? Thanking you Respectfully Kavya > On 04/06/2011 05:08 PM, ka...@ssl.serc.iisc.ernet.in wrote: >> Dear users, >> >> Is there a possibility that both non-merohedral twinning >> and partial hemihedral twinning occur in the same crystal? >> In one of the data in R3, sfcheck indicated twinning and thus >> upon using twinning option during refinement, refmac considered twinning operator of (k h -l). But the images also show some >> interpenetrating lattice spots which are characteristics of >> non-merohedral twinning. >> >> Probably one of the lattices have been more prominent >> and hence detected and processed by mosflm with an overall >> Rmerge of 8.2 at 2.35 Ang resolution. >> >> So is there such a possibility? >> >> Thanking you >> With Regards >> Kavya >> >> > > -- > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed to be clean. > > -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.
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