It is puzzling that in the high res shell (to 3.1A) CC(1/2) is 0.533 (OK), but I/sigI is 0.1 (v low). Is the SDcorrection (SDFAC, SDADD) sensible (and “Analysis of standard deviations vs. intensity”)? In Aimless the determination of SDFAC and SDADD sometimes go haywire - with high multiplicity you could try “SDCORRECTION SAMPLESD” to see what it does to mean I/sigI
Is there a lot of radiation damage (you say not, but if so with the high multiplicity you could cut the end of the data)? At least the data can’t be anisotropic in the cubic space group! Probably none of this helps in improving maps. It may be worth looking at sharpened maps (from refmac or in coot) Phil > On 18 May 2017, at 12:47, Michael Jarva > <00001295eb3572d0-dmarc-requ...@jiscmail.ac.uk> wrote: > > Dear all, > > I have a dataset that have two very interesting properties: a) It's in I432, > and b) has a whooping 75% solvent content. > You might think that the solvent content obviously is a big red flag, and so > did I, but I have phased this successfully with just one monomer, and the > packing result does makes a lot of sense. The resulting maps contain no extra > umodelled blobs, and trying to phase it with an additional molecules does not > give a good solution. > > The problem I have is that the diffraction intensity/Rmerge plummets/explodes > around the 3.5Å mark (I assume because of the high solvent content) to such > an extent that even though I have little radiation damage, 100% completeness > in high resolution shells, and very high redundancy, any attempt to merge the > dataset at a higher resolution has so far given no improvement to the maps. > > I'm hoping that there might be a few tricks out there I can apply to the spot > finding/integration/scaling steps have it merge in a even slightly higher > resolution than I currently have been able to do. > Although I have a feeling that the only thing I can do is to grow another, > much bigger, crystal… > > many thanks for any feedback > /michael > > See below for sample outputs from aimless: > > Overall InnerShell OuterShell > Low resolution limit 43.50 43.50 3.32 > High resolution limit 3.10 8.78 3.10 > > Rmerge (within I+/I-) 0.079 0.010 21.891 > Rmerge (all I+ and I-) 0.081 0.011 22.502 > Rmeas (within I+/I-) 0.084 0.011 23.102 > Rmeas (all I+ & I-) 0.084 0.011 23.169 > Rpim (within I+/I-) 0.027 0.004 7.335 > Rpim (all I+ & I-) 0.020 0.003 5.450 > Rmerge in top intensity bin 0.010 - - > Total number of observations 34917 1495 6448 > Total number unique 2057 112 362 > Mean((I)/sd(I)) 18.3 130.9 0.1 > Mn(I) half-set correlation CC(1/2) 1.000 1.000 0.533 > Completeness 99.9 97.4 100.0 > Multiplicity 17.0 13.3 17.8 > > Overall InnerShell OuterShell > Low resolution limit 43.50 43.50 3.84 > High resolution limit 3.50 8.58 3.50 > > Rmerge (within I+/I-) 0.052 0.011 2.422 > Rmerge (all I+ and I-) 0.056 0.012 2.659 > Rmeas (within I+/I-) 0.055 0.011 2.553 > Rmeas (all I+ & I-) 0.058 0.013 2.738 > Rpim (within I+/I-) 0.017 0.004 0.804 > Rpim (all I+ & I-) 0.014 0.003 0.644 > Rmerge in top intensity bin 0.010 - - > Total number of observations 24596 1690 6071 > Total number unique 1462 120 343 > Mean((I)/sd(I)) 25.8 132.0 1.0 > Mn(I) half-set correlation CC(1/2) 1.000 1.000 0.771 > Completeness 99.8 97.6 100.0 > Multiplicity 16.8 14.1 17.7 > >
