<br>Dear users,<br clear="all">
<div style="text-align:justify;direction:ltr" dir="ltr"><br>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. <br>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?</div>
<div style="text-align:justify;direction:ltr" dir="ltr"> </div>
<div style="text-align:justify;direction:ltr" dir="ltr">Thanks in advance.</div>
<div style="text-align:justify;direction:ltr" dir="ltr"> </div>
<div style="text-align:justify;direction:ltr" dir="ltr">Yours,</div>
<div style="text-align:justify;direction:ltr" dir="ltr">Mohaddeseh</div>---------------------------------------------------------<br><br>Mohaddeseh Abbasnejad, <br>Room No. 323, Department of Physics, <br>University of Tehran, North Karegar Ave.,<br>
Tehran, P.O. Box: 14395-547- IRAN <br>E-Mail: <a href="mailto:m.abbasnejad@gmail.com" target="_blank">m.abbasnejad@gmail.com</a><br>
Website: <a href="http://physics.ut.ac.ir" target="_blank">http://physics.ut.ac.ir</a><br><br>---------------------------------------------------------<br><br>