It is actually possible to calculate R(free) with SHELXL for the outer
most resolution shell. Gabor Bunkoczi indicated the solution and I
forward it here to the public:
- Rename the .res file of the last refinement run to .ins
- adjust the CGLS parameter in the .ins file to 0 -1 (Zero refinement
cycles, selection of reference set with the flag -1):
CGLS 0 -1
- Set the resolution limits to the ones of the outer most resolution
shell (in my case 1.39-1.34 Angstroem):
SHEL 1.39 1.34
- re-run the job with the modified .ins file
- the R1(Free) values in the output .res file correspond to those of the
highest resolution shell.
Gabor, thank you very much for this great suggestion!
Oliv
Dr G. Bunkoczi schrieb:
Hi Oliv,
you can include a SHELL command (set to the highest resolution shell),
and CGLS 0 -1 and re-run the job. The R-factors you get are those of
the highest resolution shell.
BW, Gabor
On Oct 8 2007, Oliv Eidam wrote:
Dear all,
I used SHELXL for anisotropic structure refinement of high-resolution
data (1.3 Angstroem) and a reviewer asked me to include refinement
statistics for the outer most resolution shell in the
crystallographic table. While R-factors for the outer most resolution
shell belong to the standard output in REFMAC or CNS, it seems to me
that SHELXL calculates R-factors only for reflections of the work
set. I also noticed that test reflections are missing in the
structure factor file (.fcf file) generated by shelxpro, preventing
me to use the [S] or [L] options in shelxpro to calculate R(free)
statistics.
Is it simply not possible to calculate the R(free) factor for the
outer most shell after SHELX refinement? Or is there a problem with
my SHELX program?
Many thanks for your answers and suggestions,
Oliv
--
Oliv Eidam
Department of Biochemistry
University of Zurich
Winterthurerstrasse 190
8057 Zurich, Switzerland
Phone: 0041-44-635-6563
Email: [EMAIL PROTECTED]
Web: http://www.bioc.uzh.ch/gruetter
NCCR: http://www.structuralbiology.ethz.ch
