Name
Material
Comment
Yamamoto's software P
REMOS,PREMOS,MODPLT and PRJMS
JANA P
Crystallographic computing system for standard, modulated and composite crystals
XND P
Rietveld refinement. See also
CPD newsletter .
SIMPRO P
Full Powder Pattern Fitting Program
SIMREF P
Simultaneous Rietveld Refinement
QuasiTiler 3.0 P
Program written by Eugenio Durand, at the Geometric Center, for drawing Penrose tilings
and its generalizations. The page contains also an introduction to the geometry of
quasicrystals. QuasiTiler is implemented as a HTML fill-out form.
S. Weber's programs P
Many JAVA applets and applications.
CSECM P
See Superspace Tools in this table.
Phonon Software P
Calculates phonon dispersion relations and phonon
density of states of crystals from force constants
or Hellmann Feynman forces found by an ab initio
program
Nada P
Program for refinement of q vectors up to 6 dimensions from CCD and Imaging plate data.
tilings.exe P
The program generates Ammann-Beenker and Penrose quasicrystal structures with
various parameters.
DIMS P
Ab-initio direct-method phasing of diffraction data from
incommensurately modulated/composite crystals
VEC P
Visual computing in Electron Crystallography, including
structure-solving programs DIMS and MIMS for incommensurately modulated/composite crystals
Tiling P
Two programs for Mathematica to obtain quasiperiodic tilings using the generalized
grid method (GDM). See also
Z. Kristallogr. 218 ,
397 (2003)
Superspace Tools in Lausanne P
On line tools concerning mostly the superspace symmetry.
Crystal Symmetry Environment database (CSE) .
Recently reincarnated from the CSESM project of Janssen, Janner, Thiers and Ephraim, this database provides
information concerning space groups of arbitrary dimensions. It allows manipulation and inspection of the
groups, e.g. generators, Wyckoff positions, point group symmetry and systematic extinctions.
Space groups of 2-,3-,4- and (3+1)- dimensions are currently available. The new Java interface
enables the visualisation of structures possessing a selected space group.
NADA . Based on the orientation matrix of the main reflections and rough estimates
of the modulation wave vector(s) components, NADA re-indexes the peaks (main and satellite reflections)
with integers in higher dimensions (hklm1, hklm1m2 or hklm1m2m3, respectively) and then simultaneously
refines the orientation matrix and modulation wave vector(s) components. Refinement is carried out by the
least squares method using the observed spatial peak positions. Standard uncertainties on all refined
parameters are calculated analytically.
Superspace group finder . This database provides all potential transformations of
(3+1)D superspace groups into 3D space groups for commensurate modulation, listing possible options
for q-vector components, t-values and origin shifts of consequent superstructures. The method is based
on 3-dimensional rational cuts and enables a common (3+1)D superspace group between different
members of a structural family to be found. Alternatively, you may explore 3D space groups resulting
from a (3+1)D superspace group. The project has been conceived in order to exploit possibilities
offered by the superspace concept with the aim of finding a common denominator in a series of
structures based on a limited number of structural blocks, i.e. modular structures.
List of (3+1) dimensional superspace groups . According International Tables for
Crystallography (1999) nomenclature, Volume C, Table 9.8.3.5.
Bravais classes: 4D to 3D correspondence . This page shows potential transformations
of (3+1)D Bravais classes into 3D classes for commensurate modulation, listing possible options for
q-vector components and orientation of consequent superstructures.
Rational approximator . How far from a rational expression is your incommensurate
q-value? This applet converts real numbers into the closest rational number with the
smallest denominator e.g. 0.85714285 => 6/7.
Superspace Harvester . The applet 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 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.
Superflip P
Program for solution of three or more dimensional structures by the charge flipping method.
INJAVIS P
An interactive molecular dynamics JAVA applet to demonstrate self-assembly of identical particles to a decagonal
quasicrystal in two dimensions.
What's new
Go to the European Crystallographic Association page