Bilbao Crystallographic Server => Symmetry mode analysis Help

AMPLIMODES: Symmetry mode analysis

AMPLIMODES for FullProf Suite and Jana2006

Symmetry mode analysis
AMPLIMODES carries out a symmetry-mode analysis of a displacive phase transition. Starting from the experimental structures of the high- and low symmetry phases, the program determines the global structural distortion that relates the two phases. The symmetry modes compatible with the symmetry break are then calculated. Their orthogonality permits the decomposition of the global distortion, obtaining the amplitudes of the different symmetry-adapted distortions present in the structure, as well as their corresponding polarization vectors.

The input of the program consists of:
  • The information about the structures of the high- and low symmetry phases: Space group number, lattice parameters and relative atomic coordinates of the asymmetric unit.
  • The transformation matrix that relates the basis of the two space groups.

AMPLIMODES tutorial: download
FullProf tutorial: download

NEW: The output of AMPLIMODES (saved as an html file) can now be directly read by Jmol. This Java viewer allows to visualize in 3D in a straightforward manner all distortion modes of the output, with arrows and/or dynamically, as virtual vibration modes.

If you are using this program in the preparation of a paper, please cite it in the following form:

D. Orobengoa, C. Capillas, M.I. Aroyo & J.M. Perez-Mato J. Appl. Cryst. (2009), A42, 820-833.

J.M. Perez-Mato, D. Orobengoa and M.I. Aroyo."Mode Crystallography of distorted structures".Acta Cryst A (2010) 66 558-590

If you are interested in other publications related to Bilbao Crystallographic Server, click here.

Structure Data
[in CIF format]

HINT: [ The option for a given filename is preferential ]
High Symmetry Structure
Structure Data
[in CIF format]

HINT: [ The option for a given filename is preferential ]
Low Symmetry Structure
Maximum Δ [ Maximum distance allowed ]

Transformation matrix from high-symmetry setting to low-symmetry one:

In abc format: for instance: c,a-b,a+b; 0 0 0
Or in matrix form:
           Origin shift
a        a        a                   a
+        +        +       
b        b        b                   b
+        +        +       
c        c        c                   c
If you do not know the transformation matrix relating the two structures, you can proceed to STRUCTURE RELATIONS to calculate possible transformation matrices.
If the structures are given in a non-standard setting please check here
If you want to make the pairings by hand check here

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