Hi Juergen, the original calculation was done with I/SIG's from
scala. Yes, I am aware of the problems obtaining reliable and
meaningful I/SIG with CCD data. I have gone through the exercise of
trying to get agreement between scala and scalepack by optimizing
error model parameters ... though not yet with this particular
dataset. Keep in mind that these are nearly identical datasets
(actually the same Bragg reflections), so it is a relative
improvement figure and not absolute I/SIG that are relevant here.
I had not thought to go as far as density comparison. That's a good
idea. Unfortunately the datasets were kept incomplete on purpose to
reduce possible radiation damage effects.
Richard
On Nov 26, 2007, at 11:38 AM, Juergen Bosch wrote:
Richard Gillilan wrote:
I am currently working on guidelines for when helium and
microbeam are necessary (based on both simulations and explicit
measurements). At the present time, my feeling is that crystals
below 50 micron can certainly make the extra hassle worthwhile.
It really depends upon how badly you want that extra resolution.
In the case above, it pushed the resolution from above to below
the 2.0 Angstrom mark based on I/SIG.
Hi Richard,
I/SigI based on which program ? Default modes or tweaked by
expert ? I would give this particular dataset a chance to be
processed by all available programs and then do the comparison, or
actualy all the datasets you have with various setups. Should be a
nice table comparing program X versus Y and Z with the given data.
And if it's SeMet data that would even be better - runnig e.g.
Shelx and demonstrating which setup leads to an interpretable
electron density.
Juergen
--
Jürgen Bosch
University of Washington
Dept. of Biochemistry, K-426
1705 NE Pacific Street
Seattle, WA 98195
Box 357742
Phone: +1-206-616-4510
FAX: +1-206-685-7002
Web: http://faculty.washington.edu/jbosch
