<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:12pt">Hi,<br><br>First of all I would recommend the use of PlotPhon utility to plot phonon dispersion relations. For this one you have to have calculated interatomic force constants matrix (*.fc) file.<br><br>Regarding your particular question: you should choose K(0.75,0.75,0), then from the K point go to the X point (1, 1, 0) which is equivalent to <br>the X(1,0,0) point. Then from the X(1,0,0) to the Gamma (0,0,0) point.<br>Dashed line just means that we can continue in this direction to match phonons at the X point (i.e. it is an intermediate point from the Gamma to the X point) .<br><br>Please also provide your affiliation.<br><br>Bests,<br>Eyvaz<br> <br><div>-------------------------------------------------------------------<br></div>Prof. Eyvaz Isaev, <br>Department of Physics,
Chemistry, and Biology (IFM), Linkoping University, Sweden <br>Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, <br>isaev@ifm.liu.se, eyvaz_isaev@yahoo.com<div><br></div><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Tahoma" size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> lucking-pine <songsong19840614@gmail.com><br><b><span style="font-weight: bold;">To:</span></b> Pw_forum@pwscf.org<br><b><span style="font-weight: bold;">Sent:</span></b> Fri, May 6, 2011 2:50:16 PM<br><b><span style="font-weight: bold;">Subject:</span></b> [Pw_forum] why K-X point of phonon dispersion is wrong?<br></font><br>
<p>My pwscf is used in calculating Si phonon dispersion.The trend of picture in </p>
<p>most special Symmetry is right.But the only K-X is wrong.I use Xcrysden to </p>
<p>get K-point.<br>I found most paper is dash line in 'K' point.So what is mean? Please anyone </p>
<p>could tell me! Thanks!<br>The attachment is my picture and reference paper.</p>
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