Your main problem is not the ice rings but a wrong lattice/indexing solution. R factors are very high for even low res shells and I/sigma very low. To me this tells you are not finding your diffraction spots at all.
First thing to try: Take more images for the indexing step and use only the strongest spots. And do not refine distance during indexing, as you probably have a pretty high mosaicity. Petri On Oct 14, 2011, at 7:12 AM, ChenTiantian wrote: > Hi there, > I am processing a dataset which has bad ice rings (as you can see in the > attach png file). > I tried both XDS and imosflm, and got similar results, it seems that adding " > EXCLUDE_RESOLUTION_RANGE" cannot get rid of the effects of the ice rings. > the following is part of the CORRECT.LP which is the second attached file, > you can find more details there. > > SUBSET OF INTENSITY DATA WITH SIGNAL/NOISE >= -3.0 AS FUNCTION OF RESOLUTION > RESOLUTION NUMBER OF REFLECTIONS COMPLETENESS R-FACTOR R-FACTOR > COMPARED I/SIGMA R-meas Rmrgd-F Anomal SigAno Nano > LIMIT OBSERVED UNIQUE POSSIBLE OF DATA observed expected > Corr > > 4.24 37152 5537 5545 99.9% 46.9% 52.7% > 37150 2.48 50.8% 19.4% -28% 0.513 5136 > 3.01 55344 9002 9840 91.5% 62.7% 65.1% > 55116 1.76 68.3% 48.1% -28% 0.520 7760 > 2.46 84636 12699 12703 100.0% 67.4% 84.7% > 84634 1.55 73.0% 54.2% -19% 0.513 12104 > 2.13 97910 14743 14987 98.4% 254.5% 199.3% > 97908 0.16 276.2% 4899.9% -23% 0.473 14037 > 1.90 110260 16846 16940 99.4% 299.2% 303.3% > 110245 0.06 325.0% -99.9% -17% 0.422 15995 > 1.74 118354 18629 18744 99.4% 1062.0% 1043.6% > 118317 -0.20 1156.4% -99.9% -13% 0.380 17414 > 1.61 122958 20193 20331 99.3% 967.5% 1571.1% > 122868 0.10 1059.7% 987.3% -2% 0.402 18348 > 1.51 125075 21554 21794 98.9% 838.9% 1355.1% > 124933 0.08 922.6% 1116.9% -1% 0.402 18977 > 1.42 72057 17042 23233 73.4% 640.8% 775.3% > 70391 0.08 732.5% 826.7% -8% 0.425 10003 > total 823746 136245 144117 94.5% 166.4% 166.7% > 821562 0.40 181.1% 296.7% -15% 0.435 119774 > > Note that I/SIGMA of each resolution shell is <2.5, so how should I do to > process the dataset properly? Any suggestion about this super ice rings? > Thanks! > > Tiantian > > -- > Shanghai Institute of Materia Medica, Chinese Academy of Sciences > Address: Room 101, 646 Songtao Road, Zhangjiang Hi-Tech Park, > Shanghai, 201203 > <csrc.png><CORRECT.LP> --- Petri Kursula, PhD Group Leader, Docent of Neurobiochemistry Department of Biochemistry, University of Oulu, Finland Department of Chemistry, University of Hamburg, Germany Visiting Scientist (CSSB-HZI, DESY, Hamburg, Germany) www.biochem.oulu.fi/kursula www.desy.de/~petri petri.kurs...@oulu.fi petri.kurs...@desy.de ---
