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.
To get a tutorial about this program click here.
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.
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Symmetry mode analysis