<div dir="ltr"><div>Dear Prof. Sclauzero,<br><br></div>thank you for your exact answer. <span id="result_box" class="" lang="en"><span class="">You are absolutely right</span><span>.</span> <span class="">I found a</span> corresponding <span class="">part of the code</span><span class=""></span><span>. </span></span><br>
<span id="result_box" class="" lang="en"><span class="">My problem</span> <span class="">has been solved</span><span>!</span></span><div class="gmail_extra"><br><br><div class="gmail_quote">2014-08-15 15:37 GMT+06:00 Sclauzero Gabriele <span dir="ltr"><<a href="mailto:gabriele.sclauzero@mat.ethz.ch" target="_blank">gabriele.sclauzero@mat.ethz.ch</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
Dear Dmitry,<br>
<br>
I am sure there is nothing puzzling in there. When lda_plus_u is true, but all Hubbard_U’s are zero, the Hubbard component of the forces are still computed and added to the total force, but such component will be zero (try verbosity=‘high’ to get them printed on output). In the subroutine force_hub you can find the line:<br>
<div class=""><br>
forceh(ipol,alpha) = forceh(ipol,alpha) - v%ns(m2,m1,is,na) * dns(m1,m2,is,na)<br>
<br>
</div>which corresponds exactly to the formula you wrote here below. The point is that the Hubbard potential<br>
v%ns =\frac{U}{2} \sum_{Imm’} (\delta_{mm’} -2n^{I}_{m’m})<br>
depends linearly on Hubbard_U, so all its components will be zero if U=0.<br>
<br>
<br>
HTH<br>
<br>
GS<br>
<div><div class="h5"><br>
<br>
<br>
> Dear Prof. Cococcioni,<br>
><br>
> I use the QE 5.1 and It seems that the Hubbard forces are calculated well. But I'm a little puzzled by the next situation.<br>
> An analytical expression for the Hubbard forces can be written as:<br>
><br>
> F^{U}_{\alpha i} = - \frac{U}{2} \sum_{Imm'} (\delta_{mm'} -2n^{I}_{m'm}) \frac{\partial n^{I}_{mm'}}{\partial \tau_{\alpha i}}.<br>
><br>
> Here alpha is a number of displacement atom in i-direction and U is a Hubbard correction.<br>
> But I have not found the procedure of multiplication by the Hubbard U correction in the subroutines where Hubbard forces are calculated. Below the appropriate lines of the corresponding subroutines are listed:<br>
><br>
> SUBROUTINE forces()<br>
> ...<br>
> CALL force_hub(forceh)<br>
> ...<br>
> force(ipol,na) = force(ipol,na) + forcenl(ipol,na) + forceion(ipol,na) + forcelc(ipol,na) + forcecc(ipol,na) + forcescc(ipol,na) + forceh(ipol,na)<br>
> ...<br>
> END SUBROUTINE forces<br>
><br>
><br>
> SUBROUTINE force_hub(forceh)<br>
> ...<br>
> forceh(ipol,alpha) = forceh(ipol,alpha) - v%ns(m2,m1,is,na) * dns(m1,m2,is,na)<br>
> ...<br>
> END SUBROUTINE force_hub<br>
><br>
> --<br>
><br>
> Best regards,<br>
> Dr. Dmitry Novoselov<br>
><br>
> Institute for Metal Physics,<br>
> Yekaterinburg, Russia<br>
><br>
><br>
> 2014-08-14 19:43 GMT+06:00 Matteo Cococcioni <<a href="mailto:matteo@umn.edu">matteo@umn.edu</a>>:<br>
><br>
> Dear Dmitry,<br>
><br>
> it should be working. what version of the code are you using?<br>
><br>
> Matteo<br>
><br>
><br>
> On Wed, Aug 13, 2014 at 10:47 AM, Dmitry Novoselov <<a href="mailto:dnovoselov@gmail.com">dnovoselov@gmail.com</a>> wrote:<br>
> Dear all,<br>
><br>
> It seems that in the part of the code where the Hubbard forces is calculated (forces and force_hub subroutines), the Hubbard U correction does not taken into account. Is it ok?<br>
><br>
> Thank you!<br>
><br>
> --<br>
><br>
> Best regards,<br>
> Dr. Dmitry Novoselov<br>
><br>
> Institute for Metal Physics,<br>
> Yekaterinburg, Russia<br>
><br>
><br>
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><br>
><br>
> --<br>
><br>
> Best regards,<br>
> Dr. Dmitry Novoselov<br>
><br>
> Institute for Metal Physics,<br>
> Yekaterinburg, Russia<br>
><br>
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<br>
</div></div>Dr. Gabriele Sclauzero<br>
Materials Theory - ETHZ<br>
ETH Zurich, HIT G 43.2<br>
Wolfgang-Pauli-Str. 27<br>
8093 Zürich, Switzerland<br>
<br>
Phone +41 44 633 94 10<br>
Fax +41 44 633 14 59<br>
<a href="mailto:gabriele.sclauzero@mat.ethz.ch">gabriele.sclauzero@mat.ethz.ch</a><br>
<a href="http://www.theory.mat.ethz.ch" target="_blank">www.theory.mat.ethz.ch</a><br>
<div class="HOEnZb"><div class="h5"><br>
<br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br><div dir="ltr"><p><b><i><span style="border-collapse:collapse;color:rgb(51,51,51);font-family:arial,sans-serif;font-size:13px;font-style:normal;font-weight:normal"></span></i></b></p>
<div><i><span style="border-collapse:collapse;color:rgb(51,51,51);font-family:arial,sans-serif;font-size:13px"><i>Best regards,</i></span></i><br></div><div><i><span style="border-collapse:collapse"><i style="color:rgb(51,51,51);font-family:arial,sans-serif;font-size:13px">Dr. Dmitry Novoselov</i><br>
<br><font color="#333333" face="arial, sans-serif">Institute for Metal Physics,</font></span></i></div><div><i><span style="border-collapse:collapse"><font color="#333333" face="arial, sans-serif">Yekaterinburg, Russia</font></span></i></div>
<p></p></div>
</div></div>