On 11/30/2016 10:16 PM, Keller, Jacob wrote:
If you fine slice and everything is then a partial, isn't that *more* sensitive
to lack of synchronization between the shutter and rotation axis than the
wide-frame method where there's a larger proportion of fulls that don't
approach the frame edge
I am wondering whether part of the benefit of fine slicing is really increased
multiplicity in disguise. I have seen in papers that empirically things do not
improve much (or can even get slightly worse) past 0.5*SigPhi, which is the
XDS-defined version of mosaicity; according to MOSFLM’s defini
>If you fine slice and everything is then a partial, isn't that *more*
>sensitive to lack of synchronization between the shutter and rotation axis
>than the wide-frame method where there's a larger proportion of fulls that
>don't approach the frame edges (in rotation space) ? Especially if you'
There is a very nice paper by Colin Nave on Matching X-ray beam and detector
properties to protein crystals of different perfection,J Synchrotron Radiat.
2014 21, 537–546. Due to the spectral and geometric properties of in house
sources there is probably no advantage with an oscillation below
Jacob,
If you fine slice and everything is then a partial, isn't that *more* sensitive
to lack of synchronization between the shutter and rotation axis than the
wide-frame method where there's a larger proportion of fulls that don't
approach the frame edges (in rotation space) ? Especially if
Dear All,
It looks like our old Hydra died of old age, and new Hydras seem quite
expensive. We are now looking for an optimal way to transfer crystallisation
screens
from the deep well blocks into crystallisation plates. We were told
Liquidator96 from Rainin, 5-200mkl worked well and was very e
If the mosaicity is, say, 0.5 deg, and one is measuring 1 deg frames, about
half the time is spent measuring non-spot background noise under spots in phi,
which is all lumped into the intensity measurement. Fine slicing reduces this.
But I am conjecturing that there is also fine-slicing-mediated
Hi Jacob,
I may have missed completely your point but as far as my memory goes, the main argument in favour of fine slicing has always been reduction of the noise arising from incoherent scattering, which in the old days arose from the capillary, solvent, air, you
name it. The noise reduction
Dear Crystallographers,
I am curious whether the observed effects of fine phi slicing might in part or
in toto be due to simply higher "pseudo-multiplicity." In other words, under
normal experimental conditions, does simply increasing the number of
measurements increase the signal and improve p
Please ignore, wrong email thread
Leonard M. Thomas Ph.D.
Macromolecular Crystallography Laboratory
Oklahoma COBRE in Structural Biology
Price Family Foundation Institute of Structural Biology
Department of Chemistry and Biochemistry
University of Oklahoma
Stephenson Life Sciences Research Center
Hi Clyde,
We have a crystal collecting now. If it does not finish by the time our time
is up you can remove it. It is sort of a lets take some frames and see if we
can do anything with it.
Overall the run was okay, ended up with some useful information, not sure about
publishable data but we
There are reasons why MR might fail to find additional copies; perhaps a
surface loop in the search model interferes with packing. You should
probably take a look at solvent content.
On 11/30/2016 12:20 PM, Matthew Bratkowski wrote:
Hello all,
I am working on a structure in space group P4 a
Hello all,
I am working on a structure in space group P4 at a resolution of about 4
angstrom. Xtriage indicates that translational NCS is present. I am able
to solve the structure by molecular replacement with four copies in the
asymmetric unit, and there are two sets of identical copies. Howev
First - there is a useful document about possible twin laws in the CCP4
documentation. It references the SHELX description of twinning for small
molecules.
http://www.ccp4.ac.uk/html/twinning.html
It is possible in a trigonal system that you could have two twin operators
but the twinning stats sho
Hi Eike,
I wouldn't necessarily let the morphology deter you. While working on my
PhD, a colleague collected beautiful data from hollow crystals.
If the crystals collapse while looping, is it possible for you to perform
"micro-surgery" on the crystal so that you only have a single face?
Sometimes
What about spacegroups in PG 32, e.g., p3212?
JPK
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Napoleao
Fonseca Valadares
Sent: Wednesday, November 30, 2016 2:01 AM
To: CCP4BB@JISCMAIL.AC.UK
Subject: [ccp4bb] To win or not twinning?
Dear CCP4ers,
I'd like to kindly ask
Dear Peng,
The CCP4 interface for this task can be found in the menu Refinement ->
Restraint Preparation -> Merge monomer libraries.
Cheers,
Wouter
2016-11-30 13:33 GMT+01:00 Peng :
> Hello,
> I was wondering how to merge two cif files of ligands for refinement.
> Thanks,
> Peng
>
>
>
>
>
>
>
Hello,
I was wondering how to merge two cif files of ligands for refinement.
Thanks,
Peng
Hi,
The significant difference of refinement R values of the two models,
single vs twinned crystal, indicates that the later is a far superior
model of your crystal, corroborated its lower difference in Rfree-Rwork.
However, I am curious about the refined twinning fraction, did it
decrease
Dear Eike,
The fact that the crystal is hollow, won’t ruin your diffraction, as long as
the crystal remains rigid. However, when the crystal is flexible and collapses
during mounting and freezing, you are in trouble. Against the good practice, I
would in this case try a big loop and scoop the c
Dear Napo,
For me this looks like a correct treatment of a twinned crystal. What more do
you want/expect?
Best,
Herman
Von: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] Im Auftrag von Napoleao
Fonseca Valadares
Gesendet: Mittwoch, 30. November 2016 08:01
An: CCP4BB@JISCMAIL.AC.UK
Betreff
Dear all,
I had this experience: going pedantically to the individual points the RSRZ
and other validation statistics in the form were reporting - in a vast
majority of the cases nothing was wrong at all. So it seems to be somewhat
overdoing its job - not that this is bad on its own - but we are lo
22 matches
Mail list logo
