Hi, 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.
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 the X(1,0,0) point. Then from the X(1,0,0) to the Gamma (0,0,0) point. 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) . Please also provide your affiliation. Bests, Eyvaz ------------------------------------------------------------------- Prof. Eyvaz Isaev, Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com ________________________________ From: lucking-pine <[email protected]> To: Pw_forum at pwscf.org Sent: Fri, May 6, 2011 2:50:16 PM Subject: [Pw_forum] why K-X point of phonon dispersion is wrong? My pwscf is used in calculating Si phonon dispersion.The trend of picture in most special Symmetry is right.But the only K-X is wrong.I use Xcrysden to get K-point. I found most paper is dash line in 'K' point.So what is mean? Please anyone could tell me! Thanks! The attachment is my picture and reference paper. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110506/81b8148d/attachment.htm
