  Group Theory techniques can aid greatly the determination of magnetic
structures. The integration of their calculations into new and existing
refinement programs is an ongoing development that will simplify and make more
rigorous the analysis of experimental data. This paper presents an overview of
the practical application of symmetry analysis to the determination of magnetic
structures. Details are given of the different programs that perform these
calculations and how refinements can be carried out using their results.
Examples are presented that show how such analysis can be important in the
interpretation of magnetic diffraction data, and to our reasoning of the causes
for the observed ordering.
