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CCP14
Methods, Problems and Solutions
Software for Incommensurate/Modulated Structures
Originally via
Rietveld Mailing List
Summary of Incommensurate/Modulated Structure Programs for Powder Data and Single Crystal
Summary of Programs for Powder Data and Single Crysal that can refine
Incommensurate/Modulated Structures
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Hi,
Following is a summary of programs that can handle
Incommensurate/Modulated Structures. Additions/corrections
most welcome.
Superflip
- Lukas Palatinus and Gervais
Chapuis
Windows,
MacOSX and source code
This program
allows a solution of crystal structucure in arbitrary dimension using
the charge-flipping algorithm.
It
can thus be used to solve periodic structures as well as
incommensurately modulated structures, composites and even
quasicrystals.
Web Site
Helps
to find a superspace model for a set of structures by simulating the
diffraction pattern for each structure on a semi-transparent
layer.
By
superposing the layers you identify common spots which in the
superspace approach would correspond to the same main
reflection.
All
other peaks are expected to be satellites - different colors attributed
to patterns help you figure out a modulation for each particular case.
Drag-and-drop
CIF files to the program window to start exploring.
List
of (3+1) dimensional superspace groups
(3+1)D groups
according International Tables for Crystallography (1999), Volume C,
Table 9.8.3.5.
Web Site
Original at http://superspace.epfl.ch/groups/
MXD (Mixed data
eXecutive) - Pierre Wolfers
DIMS
Direct Methods for Incommensurate Modulated/Composite Structures - Fan,
Hai-fu & colleagues
- Contact: [email protected]
- WEB
SITE
- UNIX, Windows95, 98, NT and 2000
- DIMS (Direct-methods
for Incomensurate Modulated Structures)
deals with one-dimensionally modulated structures and composite
structures consists of two sub-systems. For incommensurate modulated
structures, the program calculates E-values independent of atomic
scattering factors, hence it can accept diffraction data from X-rays,
electrons or neutrons and treat them in the same way. However, for
composite structures DIMS can deal with only X-ray diffraction data.
- Stand-alone version:
- The
program is written in Fortran. In theory, it can be run in any
operating system provided appropriate Fortran compiler is available.
- The program accepts two-line symbols of
superspace groups and derives accordingly symmetry generators.
Alternatively, it allows also manual input of symmetry generators.
- Incommensurate modulated/composite
structures are solved by direct methods in two stages. In the first
stage, phases of main reflections are derived using a conventional
direct-method, while in the second stage, phases of satellite
reflections are derived by a multi-dimensional direct method with
starting phases of main reflections.
- In case the basic/average structure is
known, phases of main reflections calculated from which can be input to
DIMS and the first stage should be skipped.
- Windows
version:
- The
Windows version of DIMS forms a part of the program
VEC.
- I/O data of DIMS can be displayed and
manipulated by the sophisticated graphic interface of VEC. 4D-Fourier
maps phased by DIMS can be calculated, displayed and interpreted within
VEC. The subroutine
MIMS can help with building a
4D-structure model from the 4D-Fourier map.
- Tutorial at
http://cryst.iphy.ac.cn/VEC/Tutorials/DIMS/DIMS.html
- [
CCP14 UK Web Mirror] | [
Canadian CCP14 Mirror]
- Download at
http://cryst.iphy.ac.cn/Download/download.html
- [
CCP14 UK Web Mirror] | [
Canadian CCP14 Mirror]
Fullprof Rietveld
- Juan Rodriguez-Carvajal and WinPlotr Interface -
T. Roisnel
Fullprof/WinPlotr
Download - CNRS, France
JANA2000 Single
Crystal and Powder Diffraction Software Website - Vaclav
Petricek
- Contact: [email protected]
- WEB
SITE
- UNIX, VMS
and DOS
- Single
Crystal and Powder Diffraction Structure Refinement Suite for Normal
and Incommensurate Structures. UNIX, VMS and DOS. What's New includes:
- Jana2000
supports refinement of standart and modulated structures from powder
data. The support for powders is integrated in the interface already
used for single crystals.
- Jana2000
enables electron density studies.
- f' and
f'' refinement
- Better
support for 5d structures. With older versions 5d structures were only
supported by Refine and Fourier. Now the following features have been
added: calculation and visualisation of t-maps by Contour. Calculaton
of distances by Dist. Export to given 3d volume by Editm40. Support for
combination of 4d data sets measured for particular q-vectors of a 5d
structure.
- File-Save
As saves a structure with a different jobname.
- File-History
lists 15 last opened structures. Jana2000 automatically openes the last
used structure.
- Warning
for PC users: the PC version of Jana2000 available by ftp does not work
with Pentium II and lower processors. We supply special version built
for these processors.
- PC
version is now 32 bit program for Windows9x/NT/2000. The DOS version is
no longer supported.
- Original at http://www-xray.fzu.cz/jana/jana.html
- [CCP14
UK Web Mirror] | [Canadian
CCP14 Mirror] |
[Australian
CCP14 Mirror]
Jana2000 Single
Crystal and Incommensurate Structure Solution Suite - Vaclav
Petricek
REMOS and Superspace groups for 1D and 2D
Modulated Structures - Akiji Yamamoto
Simref Rietveld,
Simpro Profile Refinement - Harold Ritter
VEC
Visual Computing in Electron Crystallography - Fan, Hai-fu &
colleagues
- Contact: [email protected]
- WEB
SITE
- Windows95, 98, NT and 2000
- VEC is a program for
visual computing in electron crystallogarphy with the following main
features:
- Preliminary
processing of electron microscopy images
- Indexing and extracting intensities of
electron diffraction patterns
- Searching defocus value from a single
electron microscopy image
- Resolution enhancement of electron
microscopy images using direct methods
- Simulation of dynamical/kinematical
electron diffraction patterns and electron microscopy images for
conventional and modulated crystals
- 2-, 3- and 4-dimensional FFT
- 2-dimensional half-tone-graph display
of 2-, 3- and 4-dimensional Fourier maps
- Contour mapping of 2-dimensional
patterns
- Ab-initio
direct-method solution of incommensurate one-dimensionally modulated
structures and composite structures of two subsystems
- Tutorial at
http://cryst.iphy.ac.cn/VEC/Tutorials/MAIN.html
- [
CCP14 UK Web Mirror] | [
Canadian CCP14 Mirror]
- Download at
http://cryst.iphy.ac.cn/Download/download.html
- [
CCP14 UK Web Mirror] | [
Canadian CCP14 Mirror]
XND Rietveld On-Line Manual -
Jean-Francois Berar
XND
Rietveld FTP Site
- Jean-Francois Berar
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