<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">><br>> if you have a look to the file resp_mat.f90 you can check the reason <br>> to have atomic positions read from file.<br>> there are needed to calculate the matrix elements of chi and chi0.<br>><br>Nevertheless I don't understand why it is necessary to know atomic position to calculate chi which is dn/dalpha derivative. Isn't it a slope of n(alpha) function?<br><br>><br>> if you are considering a FeO unit cell with 8 ions you can perturb <br>> only one Fe site (you don`t need to look at occupancies on O sites) <br>> if all the other Fe are equivalent to this one.<br>> one have to perturb once all the ions which are not equivalent.<br>><br>In this case what is the definition of equivalence of the ions? <br><br>Maxim<br><br>--- On <b>Wed, 2/17/10, 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] questions about lda+u calculation<br>To: "PWSCF Forum" <pw_forum@pwscf.org><br>Date: Wednesday, February 17, 2010, 1:03 AM<br><br><div class="plainMail">Gianluca Giovannetti wrote:<br>> Dear Ivanov,<br>><br>> if you have a look to the file resp_mat.f90 you can check the reason <br>> to have atomic positions read from file.<br>> there are needed to calculate the matrix elements of chi and chi0.<br>><br>> atomic positions are given in fractional coordinates (direct lattice).<br>> what about primitive vectors?<br><br>their length is not important (as long as you maintain the symmetry of <br>the actual unit cell). the code uses them<br>to compute distances between atoms and to recognize neighbors in the <br>same shell.<br><br>><br>> if you are considering a FeO
unit cell with 8 ions you can perturb <br>> only one Fe site (you don`t need to look at occupancies on O sites) <br>> if all the other Fe are equivalent to this one.<br>> one have to perturb once all the ions which are not equivalent.<br>><br>> cheers,<br>><br>> Gianluca<br>><br>> 2010/2/16 Максим Иванов <<a ymailto="mailto:maaaxim@yahoo.com" href="/mc/compose?to=maaaxim@yahoo.com">maaaxim@yahoo.com</a> <mailto:<a ymailto="mailto:maaaxim@yahoo.com" href="/mc/compose?to=maaaxim@yahoo.com">maaaxim@yahoo.com</a>>><br>><br>> Dear PW-users,<br>> I have question about calculating the response matrice in lda+u<br>> calculation. At the tutorial with examples at page<br>> <a href="http://media.quantum-espresso.org/santa_barbara_2009_07/index.php"
target="_blank">http://media.quantum-espresso.org/santa_barbara_2009_07/index.php</a><br>> is used input file to calculate the matrice. In this input file<br>> you need file containing the atomic positions and the vectors of<br>> the unit cell plus number of unit cells in each direction to<br>> construct the supercell. As I understand response matrice is<br>> resiprocal matrix of matrix containing dn/dalfa derivatives. So,<br>> why does author include atomic positions in his program?<br>> In the case when there are more than two Fe atoms in FeO unit cell<br>> (let's say 8) is it correct to make perturbation only for one Fe<br>> atom? Or should I make perturbation for 8 Fe atoms and calculate<br>>
8x8 matrix?<br>> Thanks in advance,<br>> Maxim Ivanov<br>><br>> <br>><br>><br>><br>><br>><br>> Вы уже с Yahoo!? Испытайте обновленную и улучшенную. Yahoo! Почту<br>> <<a href="http://ru.mail.yahoo.com" target="_blank">http://ru.mail.yahoo.com</a>>!<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> <mailto:<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>><br>><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>> <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>