Introduction:
Flipsmall is a Python script that creates an input file for Superflip, and runs Superflip and EDMA to provide an automated structure solution (including symmetry determination) for small-molecule compounds. The input to flipsmall is a standard SHELX .ins file with cell info (CELL) and
scattering factor type info (SFAC). The user should install Superflip and EDMA somewhere in the path, so that it can be found by flipsmall.
The name of the executable of Superflip is usually superflip (lowercase); the name of the executable of EDMA is usually EDMA (upper case).
Similarly flipsmall can be installed in the path as well. Python (most probably at least 2.5) should be installed and accessible and Superflip and EDMA
should obviously be as well in the path. The script can be executed on Linux distributions as well as under DOS, and most probably under MacOS.
Execution:
flipsmall.py name.ins
where name is the generic name of the .ins file with accompanying name.hkl file.
The only lines really needed in .ins file are TITL, CELL, and SFAC. The cell parameters have to be constrained to their crystal system. The file name.hkl is a SHELX-type (HKLF4) reflection file with Fortran format (3i4,2f8.0).
The script creates a file name.inflip which contains a low-symmetry space group within its crystal system, which is derived from the cell parameters. This is of course a crude approach, and serves only for reflection averaging. The actual symmetry is determined by Superflip after the structure solution.
When Superflip is finished, a new .inflip file is created on the fly with the symmetry proposed by Superflip.
Then EDMA is started and the map is interpreted. EDMA creates a file name.res with the proposed structure.
Command line options
flipsmall.py name.ins merge=no gives the possibility to do charge flipping without averaging the reflection data in the Laue class; with this option the solution is truly in P1
flipsmall.py name.ins normalize=yes gives the possibility to do CF with local normalizing
flipsmall.py name.ins trial=5 gives the possibility to do charge flipping with five (or another number) different trials. The best map is used
for further processing
flipsmall.py name.ins forcesymmetry=yes gives the possibility to use (and keep) the symmetry that is proposed in the .ins file. In that case the symmetry
cards should obviously be present in the .ins-file
flipsmall.py name.ins cleanup=no does not delete intermediate files and notably the log file
flipsmall.py -h gives on-line help and some more commandline options
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