Dear Huw,
It looks as though you have correctly diagnosed a problem with AMPLE.
For expansion from borderline partial structures, I recommend the latest
SHELXE (on my beta-test server since Jan. 20th) and experimenting with
the -O and -F switches, e.g.
-F0.9 -O100 -a30
However SHELXE is still a work in progress, so this may change in future
versions.
Best wishes, George
> Hi,
>
> I've been running Ample and I'm a bit confused about the input for the shelxe-beta auto-tracing. The input mtz for Ample has F, SIGF and FreeR and it appears that Ample converts the structure factor amplitudes to intensities using mtz2various with the FSQUARED keyword as the log file contains the following:
>
> Data line--- LABIN FP=F SIGFP=SIGF FREE=FreeR_flag
> Data line--- OUTPUT SHELX
> Data line--- FSQUARED
>
> Fs are squared on output - better to use original Is from TRUNCATE output
> Data line--- END
>
> However then shelxe is run with the command:
>
> shelxe shelxe-input.pda -a15 -q -s0.4779 -o -f -n -t3
>
> I thought that the -f flag tells shelxe that the input hkl file contains Fs not Is so this should not be present?
>
> When I run shelxe with the phaser/molrep solutions and a hkl file generated either from the merged intensities with mtz2hkl or unmerged intensities with xdsconv I get much lower CCs for the autotracing which makes sense as all of the solutions so far are rubbish! The Ample logs contain CCs>30 for all solutions which doesn't seem correct.
>
> Any information would be greatly appreciated!
>
> Thanks,
>
>
>
> Huw
>
--
Prof. George M. Sheldrick FRS
Dept. Structural Chemistry,
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-3021 or -3068
Fax. +49-551-39-22582
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