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<p>Dear Clarence Leung, <br>
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<p><span><br>
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<p><span>> But I can find the input description of turbo_EELS . <br>
</span></p>
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<p>The description of the input parameters for turboEELS is here: TDDFPT/Doc/INPUT_EELS.def
<br>
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<p><span><br>
</span></p>
<p><span>> What is the meaning of q ?</span></p>
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</span></p>
<p><span>It is a transferred momentum. Have a look at these papers:<br>
</span></p>
<p><span><br>
</span></p>
"Electron energy loss and inelastic x-ray scattering cross sections from time-dependent density-functional perturbation theory"<br>
Authors: I. Timrov, N. Vast, R. Gebauer, and S. Baroni<br>
Source: PHYSICAL REVIEW B Volume: 88 Article Number: 064301 Published: AUG 2 2013<br>
See also: PHYSICAL REVIEW B 91, 139901(E) (2015)<br>
<br>
"turboEELS - A code for the simulation of the electron energy loss and inelastic X-ray scattering spectra using the Liouville-Lanczos approach to time-dependent density-functional perturbation theory"<br>
Authors: I. Timrov, N. Vast, R. Gebauer, and S. Baroni<br>
Source: Computer Physics Communications Volume: 196 Article Number: 460 Published: 4 JUNE 2015<br>
<p><span><br>
</span></p>
<p><span><span>> How can we get (x y z) 3 Polarization direction ? use the command <span>ipol = 4 ? like the turbo_lanczos?</span></span></span></p>
<p><span><span><span><br>
</span></span></span></p>
<p><span><span><span>No, "ipol" variable is not present in turboEELS.<br>
</span></span></span></p>
<p><span><span><span><br>
</span></span></span></p>
As I wrote above, q is the transferred momentum, it is a vector. So depending on the direction of q you can get different behavior of the loss function -Im[1/eps] and Im[eps] (it depends also on the modulus of q). Have a look at this paper: I. Timrov et al.,
Phys. Rev. B 95, 094301 (2017). <br>
<p><span><span><span><br>
HTH<br>
</span></span></span></p>
<p><span><span><span><br>
</span></span></span></p>
<p><span><span><span>Iurii<br>
</span></span></span></p>
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<font style="" size="3" color="808080"><span style="color: rgb(0, 0, 0);">Dr. Iurii Timrov</span><br style="color: rgb(0, 0, 0);">
<span style="color: rgb(0, 0, 0);">Postdoctoral Researcher</span><br style="color: rgb(0, 0, 0);">
<span style="color: rgb(0, 0, 0);">Swiss Federal Institute of Technology Lausanne (EPFL</span><font style="color: rgb(0, 0, 0);"><font style="color: rgb(0, 0, 0);"><span style="color: rgb(0, 0, 0);">)</span></font></font><span style="color: rgb(0, 0, 0);">
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and Simulation of Materials </span><font style="color: rgb(0, 0, 0);"><font style="color: rgb(0, 0, 0);"><span style="color: rgb(0, 0, 0);">(THEOS)</span></font></font></font><font style="color: rgb(0, 0, 0);" size="3"><br style="color: rgb(0, 0, 0);">
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<div name="divtagdefaultwrapper" style="margin: 0px;"><span style="font-family: Calibri,Arial,Helvetica,sans-serif;"><span style="color: rgb(0, 0, 0);"></span><font style="color: rgb(0, 0, 0);" size="3"><span style="color: rgb(0, 0, 0);">CH-1015 Lausanne, Switzerland</span></font></span></div>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>发件人:</b> pw_forum-bounces@pwscf.org <pw_forum-bounces@pwscf.org> 代表 Timrov Iurii <iurii.timrov@epfl.ch><br>
<b>发送时间:</b> 2017年3月6日 22:43:42<br>
<b>收件人:</b> pw_forum@pwscf.org<br>
<b>主题:</b> Re: [Pw_forum] Error in Turbo_lanczos.x to calculate the adsorption coefficiency</font>
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<p>Dear Clarence,</p>
<p><br>
</p>
<p>When posting to pw_forum please do not forget to write your affiliation!<br>
</p>
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<p>> As far as I know, the <span>turboTDDFT is not extended to metals, <br>
</span></p>
<p><span><br>
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<p><span>Yes, you are right.<br>
</span></p>
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<p><span>> So we should use fixed occupation in the scf calculation, right?</span><br>
</p>
<p><br>
</p>
<p>Yes</p>
<p><br>
</p>
<span>> However, if I use fixed occupation in scf, the error is </span>
<div>> ' charge is wrong: smearing is needed '. Because the system considered is odd electron.
</div>
<div><br>
Then you have to use smearing. I think there is no workaround with turboTDDFT for metals: one has to extend it to metals.<br>
<br>
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<div>> What should I do to calculate the adsorption coefficiency of system with odd electrons.</div>
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<p>aBsorption, not aDsorption<br>
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<p>Probably you may try to use turboEELS, which is extended to metals. Namely, use very small q (but not exactly zero) and plot the imaginary part of the dielectric function.<br>
</p>
<p><br>
</p>
<p>HTH</p>
<p><br>
</p>
<p>Iurii<br>
</p>
<p><br>
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<font size="3" face="'Times New Roman', Times, serif" color="808080">--<br>
Dr. Iurii Timrov<br>
Postdoctoral Researcher<br>
Swiss Federal Institute of Technology Lausanne (EPFL<font color="808080"><font face="'Times New Roman', Times, serif">)</font></font>
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<font size="3" face="'Times New Roman', Times, serif" color="808080">Laboratory of Theory and Simulation of Materials
<font color="808080"><font face="'Times New Roman', Times, serif">(THEOS)</font></font></font><font size="3" face="'Times New Roman', Times, serif" color="808080"><br>
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<font size="3" face="'Times New Roman', Times, serif" color="808080">CH-1015 Lausanne, Switzerland<br>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" face="Calibri, sans-serif" color="#000000"><b>From:</b> pw_forum-bounces@pwscf.org <pw_forum-bounces@pwscf.org> on behalf of LEUNG Clarence <liangxy123@hotmail.com><br>
<b>Sent:</b> Monday, March 6, 2017 9:51 AM<br>
<b>To:</b> pw_forum@pwscf.org<br>
<b>Subject:</b> [Pw_forum] Error in Turbo_lanczos.x to calculate the adsorption coefficiency</font>
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<p>Dear PWscf users,</p>
<p><br>
</p>
<p>As far as I know, the <span>turboTDDFT is not extended to metals, So we should use fixed occupation in the scf calculation, right?</span></p>
<p><span><br>
</span></p>
<p><span>However, if I use fixed occupation in scf, the error is </span></p>
<div><br>
</div>
<div>' charge is wrong: smearing is needed '. Because the system considered is odd electron.</div>
<div><br>
</div>
<div>What should I do to calculate the adsorption coefficiency of system with odd electrons.</div>
<div><br>
</div>
<div>Many thanks,</div>
<div><br>
</div>
<div>Clarence</div>
<div><br>
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