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
