<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Dear Elie, <br><br>This error is very famous one. Please read user_guide,pdf, page 56.<br><br>Again, I have to note Subject is quite different from the content.<br><br>Bests,<br>Eyvaz<br><br>--- On <b>Wed, 6/2/10, Elie Moujaes <i><elie.moujaes@hotmail.co.uk></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: Elie Moujaes <elie.moujaes@hotmail.co.uk><br>Subject: Re: [Pw_forum] start_q, last_q, start_irr, last_irr<br>To: pw_forum@pwscf.org<br>Date: Wednesday, June 2, 2010, 5:30 PM<br><br><div id="yiv1204921002">
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Dear Eyvaz and Jeff,<br>
<br>
Thank you very much for your help. The reason I am doing this is that I am still trying to get the phonon dispersion but using other this new technique implemented in version 4.2 of QE. Everything is going well except that for q-0 (the Gamma point), I am getting an error<br>
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<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span style=""> </span>from davcio : error #<span style=""> </span>20<br><span style=""> </span>error while reading from file</font><br></span></p>
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The strange thing is that only for this point, I obtain such an error...I guess another guy posted that error earlier with the title Phonon calculations on the Grid. His name is shining star. <br>
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Jeff, thanks for your suggestion as well. Actually i am still looking at the phono dispersion as a whole but found this technqieu which merges all files at the end and takes less time (I hope!).<br>
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Regards<br>
<br>
Elie Moujaes<br>
University of Nottingham<br>
NG7 2RD<br>
UK<br> <br>> Date: Tue, 1 Jun 2010 15:39:07 -0700<br>> From: eyvaz_isaev@yahoo.com<br>> To: pw_forum@pwscf.org<br>> Subject: Re: [Pw_forum] start_q, last_q, start_irr, last_irr<br>> <br>> Dear Elie,<br>> <br>> --- On Wed, 6/2/10, Elie Moujaes <elie.moujaes@hotmail.co.uk> wrote:<br>> >I am trying to get the phonon dispersion of graphene by taking each q on >its own and performing the necessary operations (i.e using start_q, >last_q, start_irr, last_irr) then merging the points all together . Can >anyone please explain to me more about these parameters.<br>> <br>> I never used start_irr, last_irr, but I use actively start_q and last_q parameters. After you get all dynX (including dyn0) files, just collect them in a directory and run q2r.x.<br>> <br>> start_q - q-point from which ph.x starts, last_q - up to this q-point from the list of q-points written in dyn0-file. I.e. if you have 12
q-points according to dyn0-file, then you can choose any combination, start_q=1, last_q=1 (usually this one is the Gamma point), or start_q=9, last_q=12 (calculate phonons for q-points from 9th to 12th), or any other combination you like (sure, last_q >= start_q).<br>> <br>> The same meaning for start_irr and last_irr, but for irreducible representations.<br>> <br>> >I read the INPUT_PH and the examples in GRID but did not actually >understand what these mean..I got that irr is irreducible representation >but how can one set these each time one runs the calculation for a q.<br>> <br>> Specify in ph.in files the next lines:<br>> <br>> *****<br>> start_q=M<br>> last_q=N<br>> start_irr=I1<br>> last_irr=I2<br>> <br>> If M=N, only irreducible representations (IrRep) in the range I1 - I2 will be calculated for a given (defined by M) q-point. By default, all IrRep will be calculated. <br>> <br>> So
easy!<br>> <br>> Bests,<br>> Eyvaz.<br>> <br>> -------------------------------------------------------------------<br>> 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<br>> <br>> <br>> <br>> <br>> <br>> <br>> _______________________________________________<br>> Pw_forum mailing list<br>> Pw_forum@pwscf.org<br>> http://www.democritos.it/mailman/listinfo/pw_forum<br> <br><hr>Get a free e-mail account with Hotmail. Sign-up now. <a rel="nofollow"></a>
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