The software package SYMMODES (Symmetry Modes) provides the necessary tools for a group-theoretical analysis of a structural phase transition. For a given group - subgroup pair G>H the program constructs the lattice of maximal subgroups relating G and H and calculates the corresponding primary and secondary modes.

SYMMODES has been developed in colaboration with H.Stokes and D.Hatch (Brigham Young University, Utah, USA).

Input Data: In order to obtain the group - subgroup lattice G>H, input or select the numbers of the group G, the subgroup H and the transformation that relates H and G.