Re: [ccp4bb] P4132 vs. F23
You need to say what the cell dimensions are for these 2 options.. Eleanor On 29 May 2012 15:59, Andrey Lebedev andrey.lebe...@stfc.ac.uk wrote: Hi Mike. I would be more careful about incorrect space group. Yes, sometimes auto-indexing gives strange results. However, in your case two sets of crystals differ by two factors, diffraction quality and space group. Therefore it seems more likely that you have two crystal forms. Could you please send me log-files from pointless or ctruncate? Then I would be able to say something more definite. Regards Andrey On 28 May 2012, at 08:46, Mike John wrote: Hi, All, we got many datasets from crystals of our protein. when the crystal has high quality, it will be indexed as F23 (correct space group). While diffracting poorer, it will be indexed as incorrect space group P4132. The crystals are twined. My question is: Given twinning, why the correct space group F23 will be indexed as an incorrect space group P4132 for most of our crystals (most crystals has poorer quality)? Theoretical analysis of twin operator and symmetry operator to connect F23 and P4132 would be highly appreciated. Thanks Mike
Re: [ccp4bb] P4132 vs. F23
Space groups F23 and P4132 are not subgroups of each other (without invoking pseudotranslational symmetry) so they cannot be related by twinning. The end of theoretical analysis. Zbyszek Otwinowski You need to say what the cell dimensions are for these 2 options.. Eleanor On 29 May 2012 15:59, Andrey Lebedev andrey.lebe...@stfc.ac.uk wrote: Hi Mike. I would be more careful about incorrect space group. Yes, sometimes auto-indexing gives strange results. However, in your case two sets of crystals differ by two factors, diffraction quality and space group. Therefore it seems more likely that you have two crystal forms. Could you please send me log-files from pointless or ctruncate? Then I would be able to say something more definite. Regards Andrey On 28 May 2012, at 08:46, Mike John wrote: Hi, All, we got many datasets from crystals of our protein. when the crystal has high quality, it will be indexed as F23 (correct space group). While diffracting poorer, it will be indexed as incorrect space group P4132. The crystals are twined. My question is: Given twinning, why the correct space group F23 will be indexed as an incorrect space group P4132 for most of our crystals (most crystals has poorer quality)? Theoretical analysis of twin operator and symmetry operator to connect F23 and P4132 would be highly appreciated. Thanks Mike Zbyszek Otwinowski UT Southwestern Medical Center at Dallas 5323 Harry Hines Blvd. Dallas, TX 75390-8816 Tel. 214-645-6385 Fax. 214-645-6353
Re: [ccp4bb] P4132 vs. F23
Hi Mike. I would be more careful about incorrect space group. Yes, sometimes auto-indexing gives strange results. However, in your case two sets of crystals differ by two factors, diffraction quality and space group. Therefore it seems more likely that you have two crystal forms. Could you please send me log-files from pointless or ctruncate? Then I would be able to say something more definite. Regards Andrey On 28 May 2012, at 08:46, Mike John wrote: Hi, All, we got many datasets from crystals of our protein. when the crystal has high quality, it will be indexed as F23 (correct space group). While diffracting poorer, it will be indexed as incorrect space group P4132. The crystals are twined. My question is: Given twinning, why the correct space group F23 will be indexed as an incorrect space group P4132 for most of our crystals (most crystals has poorer quality)? Theoretical analysis of twin operator and symmetry operator to connect F23 and P4132 would be highly appreciated. Thanks Mike
[ccp4bb] P4132 vs. F23
Hi, All, we got many datasets from crystals of our protein. when the crystal has high quality, it will be indexed as F23 (correct space group). While diffracting poorer, it will be indexed as incorrect space group P4132. The crystals are twined. My question is: Given twinning, why the correct space group F23 will be indexed as an incorrect space group P4132 for most of our crystals (most crystals has poorer quality)? Theoretical analysis of twin operator and symmetry operator to connect F23 and P4132 would be highly appreciated. Thanks Mike
