<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Dear Matteo<br>Thanks for your help. In attachment there is outout file for U for NiO that I get from wiki.This file has three column.<br>thanks<br><br>Ali Kazempour<br>
Physics de<span style="font-weight: bold;"> </span><b>8/4/09, Matteo Cococcioni <i><matteo@umn.edu></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: Matteo Cococcioni <matteo@umn.edu><br>Subject: Re: [Pw_forum] U for Oxygen<br>To: "PWSCF Forum" <pw_forum@pwscf.org><br>Date: Tuesday, August 4, 2009, 6:59 AM<br><br><div class="plainMail"><br><br>Dear Ali,<br><br><br><br>ali kazempour wrote:<br>> Dear Matteo<br>> I used your comment and followed your example for NiO and I succeed <br>> to get U for TiO2. But in file Ur16.out I see three column .<br>><br><br>I don't have any three column section in any of my files. so if you want <br>me to help you you have to report at least a section of your output <br>file. This is a good habit actually in consideration of the fact that <br>this is not a private conversation (I would have asked
you in any case <br>as I don't remember by heart the format of any file) between me and you <br>but a message to the forum and you want other people to understand<br>what you are saying.<br><br>> The first is number of atom in supercell , second is U value for Ni <br>> atom and I don,t know the third? does the third belong to U value <br>> for Oxygen or not? Because the third column kas big value?<br>><br>><br>> another question is for isolated atom Hubbard parameter. What do you <br>> expect about the value of U for Isolated atom? Is this big value <br>> (greater than 10 eV) or it would be tiny value?<br>><br><br>I think it will be meaningless for the reasons I explained in my last <br>email. To obtain a meaningful number for the isolated atom you probably<br>have to abandon the idea to use a perturbation in the potential and <br>change instead the number of electrons directly. This means you will <br>have
to do calculations on atoms having fractional charges which <br>requires additional corrections if you use a code designed for periodic <br>systems (crystals). However I have never done this isolated atom <br>calculation of U before so I don't have more details about it.<br>I see (from a private email) you are thinking of computing U for the <br>isolated atom and to obtain a value for the crystal just by dividing by<br>the epsilon_inft. the method is proposed in<br><br><a href="http://link.aps.org/doi/10.1103/PhysRevB.74.045202" target="_blank">http://link.aps.org/doi/10.1103/PhysRevB.74.045202</a><br><br>(which I haven't re-read yet).<br><br>I see a couple of problems:<br><br>1) (not important for ZnO). suppose you have Fe3O4 with Fe2+ and Fe3+. <br>these Fe ions likely have different U. how do you obtain<br>a different number from the atomic code? would you do the calculation <br>for isolated Fe2+ and Fe3+?<br><br>2) how do you get epsilon? since it's
a linear response property I don't <br>think its calculation is any cheaper than the direct calculation of U.<br><br>regards,<br><br>Matteo<br><br>> should we choose for running the script for isolated atom only gamma <br>> point or we have to choose a fine mesh?<br>> thanks a lot<br>><br>><br>> Ali Kazempour<br>> Physics department, Isfahan University of Technology<br>> 84156 Isfahan, Iran. Tel-1: +98 311 391 3733<br>> Fax: +98 311 391 2376 Tel-2: +98 311 391 2375<br>><br>> --- On *Sun, 8/2/09, Matteo Cococcioni /<<a ymailto="mailto:matteo@umn.edu" href="/mc/compose?to=matteo@umn.edu">matteo@umn.edu</a>>/* wrote:<br>><br>><br>> From: Matteo Cococcioni <<a ymailto="mailto:matteo@umn.edu" href="/mc/compose?to=matteo@umn.edu">matteo@umn.edu</a>><br>> Subject: Re: [Pw_forum] occupation<br>> To: "PWSCF Forum" <<a
ymailto="mailto:pw_forum@pwscf.org" href="/mc/compose?to=pw_forum@pwscf.org">pw_forum@pwscf.org</a>><br>> Date: Sunday, August 2, 2009, 8:31 AM<br>><br>><br>> Dear Ali,<br>><br>> 1, -1, 0 are just spin indexes to tell the code what is the relative<br>> magnetization of the atoms (parallel, antiparallel, or none). if<br>> your system is non magnetic put all 0. or set magn = .false. and put<br>> nothing.<br>> you should look at the examples on Fe and Si as well and learn from<br>> there by comparison.<br>><br>> Matteo<br>><br>><br>><br><br><br>-- <br>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>Matteo Cococcioni<br>Department of Chemical Engineering and Materials
Science,<br>University of Minnesota<br>421 Washington Av. SE<br>Minneapolis, MN 55455<br>Tel. +1 612 624 9056 Fax +1 612 626 7246<br>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% <br><br>_______________________________________________<br>Pw_forum mailing list<br><a ymailto="mailto:Pw_forum@pwscf.org" href="/mc/compose?to=Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br><a href="http://www.democritos.it/mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/mailman/listinfo/pw_forum</a><br></div></blockquote></td></tr></table><br>