Hi, I also want to learn PlotPhon.This is a new tool since version4.2.I hope it can solve this problem.
Bests. Pine. 2011/5/16 Eyvaz Isaev <eyvaz_isaev at yahoo.com> > Hi, > > The way you used to generate q-points is somewhat unusual, but seems to be > correct. > > Try also PlotPhon utility in your QE suite. > > Bests, > Eyvaz. > > ------------------------------ > *From:* lucking-pine <songsong19840614 at gmail.com> > *To:* PWSCF Forum <pw_forum at pwscf.org> > *Sent:* Sat, May 14, 2011 5:04:44 AM > > *Subject:* Re: [Pw_forum] why K-X point of phonon dispersion is wrong? > > Dear Eyvaz Isaev: > Hi,Thanks for your help.I will read these books you Recommended. > And I want to ask that I use these k-points into <band.input>,and then the > <band.output>will auto-transform the k-point into Cartesian and units of > 2*\pi/a,and I use these output k-point in <matdyn.input>.I always get > k-point in this way.Is there something wrong? > > Bests, > Pine. > > 2011/5/14 Eyvaz Isaev <eyvaz_isaev at yahoo.com> > >> Hi, >> >> XCryDen gives you q-points coordinates with respect to basis vectors. >> But X(1,1,0) and K(3/4,3/4,0) are in Cartesian and in units of 2*\pi/a. >> >> If I am not wrong, matdyn.x uses (at least, always I used) q-points in >> Cartesian, so, you have to transform these points to Cartesian. >> Or see a text book (H.Jones The Theory of Brillouin zones and electronic >> states in crystals, or J. Callaway Energy band Theory, or >> whatever you like) to find them in Cartesian. >> >> >> Bests, >> Eyvaz. >> >> ------------------------------ >> *From:* lucking-pine <songsong19840614 at gmail.com> >> *To:* PWSCF Forum <pw_forum at pwscf.org> >> *Sent:* Wed, May 11, 2011 5:34:10 AM >> *Subject:* Re: [Pw_forum] why K-X point of phonon dispersion is wrong? >> >> Dear Eyvaz Isaev: >> Thank you for your advice.My k-point is chosen by Xcrysden.such as: >> G 0.0000000000 0.0000000000 0.0000000000 >> K -0.7500000000 -0.3750000000 -0.3750000000 >> X -0.5000000000 0.0000000000 -0.5000000000 >> G 0.0000000000 0.0000000000 0.0000000000 >> L - 0.5000000000 -0.5000000000 -0.5000000000 >> X 0.0000000000 -0.5000000000 -0.5000000000 >> W -0.2500000000 -0.5000000000 -0.7500000000 >> L -0.5000000000 -0.5000000000 -0.5000000000 >> >> and I try to use your advice through using 3 type of attempt. >> 1.only chang K,Xpoint of K-G path to K(0.75,0.75,0), X point (1, 1, 0) >> 2.all k point multipy 2 times. >> such as: >> >> G 0.0000000000 0.0000000000 0.0000000000 >> K -1.5000000000 -0.7500000000 -0.7500000000 >> X -1.0000000000 0.0000000000 -1.0000000000 >> G 0.0000000000 0.0000000000 0.0000000000 >> L - 1.0000000000 -1.0000000000 -1.0000000000 >> X 0.0000000000 -1.0000000000 -1.0000000000 >> W -0.5000000000 -1.0000000000 -1.5000000000 >> L -1.0000000000 -1.0000000000 -1.0000000000 >> >> 3.only K,Xpoint of K-G path multiply 2 times. >> such as >> >> G 0.0000000000 0.0000000000 0.0000000000 >> K -1.5000000000 -0.7500000000 -0.7500000000 >> X -1.0000000000 0.0000000000 -1.0000000000 >> G 0.0000000000 0.0000000000 0.0000000000 >> L - 0.5000000000 -0.5000000000 -0.5000000000 >> X 0.0000000000 -0.5000000000 -0.5000000000 >> W -0.2500000000 -0.5000000000 -0.7500000000 >> L -0.5000000000 -0.5000000000 -0.5000000000 >> >> However,all this attempts yield wrong picture. So,this must be something I >> didn't understand correctly.Would you tell me where is my fault ? >> 2011/5/6 Eyvaz Isaev <eyvaz_isaev at yahoo.com> >> >>> 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 <songsong19840614 at gmail.com> >>> *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. >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> Pw_forum at pwscf.org >>> http://www.democritos.it/mailman/listinfo/pw_forum >>> >>> >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110516/cadda810/attachment-0001.htm
