Dear all, My question has probably been answered already somewhere, but I could not find any hint in the mailing-list.
=> Here are my questions: Is there a tool (in espresso or somewhere else) that analyzes the symmetry of the eigenvectors of the dynamical matrix ? Can ph.x give this information in the output ? Does ph.x use symmetry arguments to simplify the diagonalizing of the dynamical matrix ? => Here is the background, in case my question are not precise enough: When I calculate the phonon dispersion of a solid, I get the phonon frequencies and eigenvectors at any q-point. As many have done before me, I want to link the frequencies at different qpoints according to their symmetry properties. For the gamma point, i can relatively easily attribute the symmetry to the different modes by looking at the eigenvectors of the dynamical matrix. But for other q-points, it gets much more complicated. I suppose i should find the sub-group of the new enlarged unit cell corresponding to the new q-point and find there which are the new symmetry of the modes in this subgroup. And then finally see how they correlate to the symmetries found at gamma point. I can do this procedure by hand a few times for high-symmetry qpoints, but for any q-point, i would just like to have a nice code helping me to avoid errors and saving time... Do you know of such a tool ? Thank you in advance, Claire ___________________________________________ Dr. Claire LOISON http://www.cpfs.mpg.de/~loison/ MPI fuer Chemische Physik fester Stoffe Noethnizerstrasse 40 D- 01187 Dresden GERMANY e-mail : loison at cpfs.mpg.de tel : +49-351-4646-4225 fax : +49-351-4646-10 ___________________________________________
