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According to the paper, the data was refined in REFMAC in 'twin mode' which, I believe, calculates the R-factor using a non-conventional R-factor equation which usually lower than the conventional R-factor. I believe this is dependent on the twin fraction which wasn't mentioned in the paper (or supplementary info) unless I missed it. Jon -- Jonathan P. Schuermann, Ph. D. Beamline Scientist NE-CAT, Building 436E Advanced Photon Source (APS) Argonne National Laboratory 9700 South Cass Avenue Argonne, IL 60439 email: [log in to unmask] Tel: (630) 252-0682 Fax: (630) 252-0687 On 02/09/2011 05:11 PM, James Holton wrote: > This was "molecular replacement" from 1jb0, so the phases came from > the model. Probably more properly called "direct refinement" since > all we did was a few cycles of rigid body. Personally, I was quite > impressed by how good the R factors were, all things considered. > > -James Holton > MAD Scientist > > On Wed, Feb 9, 2011 at 2:56 PM, Bernhard Rupp (Hofkristallrat a.D.) > <[log in to unmask] <mailto:[log in to unmask]>> wrote: > > Any idea where then phases came from? > BR > > -----Original Message----- > From: CCP4 bulletin board [mailto:[log in to unmask] > <mailto:[log in to unmask]>] On Behalf Of Thomas > Juettemann > Sent: Wednesday, February 09, 2011 12:16 PM > To: [log in to unmask] <mailto:[log in to unmask]> > Subject: Re: [ccp4bb] First images of proteins and viruses caught > with an > X-ray laser > > Thank you for clarifying this James. Those details are indeed often > lost/misinterpreted when the paper is discussed in journal club, > so your > comment was especially helpful. > > Best wishes, > Thomas > > On Wed, Feb 9, 2011 at 20:38, James Holton <[log in to unmask] > <mailto:[log in to unmask]>> wrote: > > > > As one of the people involved (I'm author #74 out of 88 on PMID > > 21293373), I can tell you that about half of the three million > > snapshots were blank, but we wanted to be honest about the > number that > > were collected, as well as the "minimum" number that were needed to > > get a useful data set. The blank images were on purpose, since the > > nanocrystals were diluted so that there would be relatively few > > double-hits. As many of you know, multiple lattices crash > autoindexing > algorithms! > > > > Whether or not a blank image or a failed autoindexing run > qualifies as > > "conforming to our existing model" or not I suppose is a matter of > > semantics. But yes, I suppose some details do get lost between the > > actual work and the press release! > > > > In case anyone wants to look at the data, it has been deposited > in the > > PDB under 3PCQ, and the detailed processing methods published > under PMID: > > 20389587. > > > > -James Holton > > MAD Scientist > > > > On 2/9/2011 10:38 AM, Thomas Juettemann wrote: > >> > >> http://www.nanowerk.com/news/newsid=20045.php > >> > >> http://home.slac.stanford.edu/pressreleases/2011/20110202.htm > >> > >> I think it is pretty exciting, although they only take the few > >> datasets that conform to their existing model: > >> > >> "The team combined 10,000 of the three million snapshots they > took to > >> come up with a good match for the known molecular structure of > >> Photosystem I." > > > > > >