Hi, This is what I thought when collecting the data - the spots did not look to be overlapping. I have actually got 4 datasets (native, mercury, iodide and platinum soaks) and they all index as the same spacegroup and unit cell (the Pt soak being slightly larger unit cell). This is of a large heterodimer, and this unit cell would put 2 in the ASU and a solvent content of 56%, so this seems reasonable.
Mosflm also picks the same unit cell, and the predictions seem to match up with spots (although mosflm predicts lots of overlaps) Cheers, Jason. -- Jason Busby PhD Student Laboratory of Structural Biology School of Biological Sciences University of Auckland Thomas Building 110 3a Symonds St Private Bag 92019 Auckland 1142 New Zealand ph: +64 9 3737599 ext 84155 fx: +64 9 3737414 On 17/07/2012, at 2:53 PM, Francis E Reyes wrote: > The cell predictions look like they're overlapping but the spots are not. At > first glance it looks like the unit cell is incorrect and is too large. > > You seem to have intense spots mixed in with weak spots at the same > resolution. Smells like multiple unit cells / cracked crystal (which if close > together would confuse the autoindex into thinking it's a larger unit cell. . > Difficult to tell without seeing the images. > > The data/spots (not the predicted spots) show reasonable separation. > > > > How does the unit cell of the derivative compare with the native? > > F > > > > On Jul 16, 2012, at 2:52 PM, Jason Busby wrote: > >> Hi, >> >> I have a crystal with a large unit cell in P21221 (a=134 b=151 c=276) and >> I'm wondering if I have a problem with overlaps. I have a native dataset, >> and am trying to get phases. I've collected a Pt soak data set on our home >> source with a 0.5˚ oscillation angle, but the anomalous signal drops off >> after about 8Å. I am wondering if this is a problem due to overlaps at >> higher resolution. >> >> The Pt dataset has been integrated with XDS, and there don't seem to be too >> many rejects, but looking at FRAME.CBF it looks like the predicted spots are >> overlapping at higher resolution. You can see a zoomed-in part of FRAME.CBF >> here: >> http://imgur.com/1WShV >> >> Should I be concerned with this? The crystal mosaicity from XDS is 0.25, so >> fairly low. What can I do about this, should I try smaller oscillation >> angles? >> >> Thanks, >> >> Jason. >> >> -- >> Jason Busby >> PhD Student >> Laboratory of Structural Biology >> School of Biological Sciences >> University of Auckland >> Thomas Building 110 >> 3a Symonds St >> Private Bag 92019 >> Auckland 1142 >> New Zealand >> >> ph: +64 9 3737599 ext 84155 >> fx: +64 9 3737414 >> > > > > --------------------------------------------- > Francis E. Reyes PhD > 215 UCB > University of Colorado at Boulder > > > > > >
