Dear users, I have plotted the harmonic frequency (obtained within the frozen phonon approach) of Diamond as a function of atomic displacements (small displacements in the [1 1 1] direction, u(1)=?(u,u,u) and u(2)=?(-u,-u,-u) are the displacements of two atoms in the basis). I expect to see a range of displacements that tend to the similar frequency, but there is no convergence in the plot. Also, the displacements with the same amplitude but different in sign, do not tend to the same frequency, which is not what I expect, too. The plot is attached. I was wondering if anyone could help me to find the source of error. I should expect the mentioned symmetry, right? Why there is no convergence?
Thanks in advance. Yours, Mohaddeseh --------------------------------------------------------- Mohaddeseh Abbasnejad, Room No. 323, Department of Physics, University of Tehran, North Karegar Ave., Tehran, P.O. Box: 14395-547- IRAN E-Mail: m.abbasnejad at gmail.com Website: http://physics.ut.ac.ir --------------------------------------------------------- -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110801/4036e4b0/attachment-0001.htm -------------- next part -------------- A non-text attachment was scrubbed... Name: fig..pdf Type: application/pdf Size: 38632 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20110801/4036e4b0/attachment-0001.pdf
