<div dir="ltr">Dear Iurii and Dario, <br><div><br></div><div>Thanks for your answers. At some point I gave up with the Davidson code since it was impossible to converge even just one excited state, this is why I switched to Lanczos. I had some hope on being able to understand the peaks but now I see that I've to try again with Davidson.</div><div><br></div><div>All my best,<br></div><div>Sergi</div></div><div class="gmail_extra"><br><div class="gmail_quote">2016-05-20 11:07 GMT+02:00 dario rocca <span dir="ltr"><<a href="mailto:roccad@gmail.com" target="_blank">roccad@gmail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div>Dear Sergi,<br></div>I would like just to add that in the examples folder of the turboTDDFT code you can find examples on<br></div>how to perform the Davidson diagonalization.<br></div>Best,<br></div>Dario Rocca<br></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="h5">On Fri, May 20, 2016 at 11:00 AM, Timrov Iurii <span dir="ltr"><<a href="mailto:iurii.timrov@epfl.ch" target="_blank">iurii.timrov@epfl.ch</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5">
<div dir="ltr" style="font-size:12pt;color:#000000;background-color:#ffffff;font-family:Calibri,Arial,Helvetica,sans-serif">
<p>Dear Dr. Sergi Vela,</p>
<p><br>
</p>
<p>With the current implementation of the Lanczos algorithm in the turboTDDFT program it is not possible to perform analysis of the origin of individual peaks in the absorption spectrum. However, such an analysis can be done using another flavor of the turboTDDFT
code, namely the turbo_davidson.x program. More information can be found in this publication:
</p>
<p><br>
</p>
<p>X. Ge, S. J. Binnie, D. Rocca, R. Gebauer, and S. Baroni, "turboTDDFT 2.0—Hybrid functionals and new algorithms within time-dependent density-functional perturbation theory", Comput. Phys. Commun. 185, 2080 (2014).</p>
<p><br>
</p>
<p>With the so-called turboDavidson code (turbo_davidson.x) you can compute the absorption spectrum (the same as with Lanczos) but as a plus in the output file you will find the information about the origin of the peaks (from which occupied level to which
empty level there was a transition and what is the corresponding intensity etc.). However, if you are interested in computing the spectrum in a very wide energy range, then turboDavidson becomes too expensive, and hence it is recommended to use the Lanczos algorithm (at
the cost described above, i.e. no information about the origin of the peaks).</p>
<p><br>
</p>
<p>HTH</p>
<p><br>
</p>
<p>Best regards,</p>
<p>Iurii <br>
</p>
<p><br>
</p>
<div>
<div name="divtagdefaultwrapper">
<div name="divtagdefaultwrapper">
<font color="808080" face="'Times New Roman', Times, serif" size="3">--<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>
</font></div>
<font color="808080"></font>
<div name="divtagdefaultwrapper">
<font color="808080" face="'Times New Roman', Times, serif" size="3">Laboratory of Theory and Simulation of Materials
<font color="808080"><font face="'Times New Roman', Times, serif">(THEOS)</font></font></font><font color="808080" face="'Times New Roman', Times, serif" size="3"><br>
</font></div>
<font color="808080"></font>
<div name="divtagdefaultwrapper">
<font color="808080" face="'Times New Roman', Times, serif" size="3">CH-1015 Lausanne, Switzerland<br>
+41 21 69 34 881</font></div>
<div name="divtagdefaultwrapper">
<a href="http://people.epfl.ch/265334" target="_blank">http://people.epfl.ch/265334</a><br>
</div>
</div>
</div>
<div style="color:rgb(33,33,33)">
<hr style="display:inline-block;width:98%">
<div dir="ltr"><font style="font-size:11pt" color="#000000" face="Calibri, sans-serif"><b>From:</b> <a href="mailto:pw_forum-bounces@pwscf.org" target="_blank">pw_forum-bounces@pwscf.org</a> <<a href="mailto:pw_forum-bounces@pwscf.org" target="_blank">pw_forum-bounces@pwscf.org</a>> on behalf of Sergi Vela <<a href="mailto:sergi.vela@gmail.com" target="_blank">sergi.vela@gmail.com</a>><br>
<b>Sent:</b> Friday, May 20, 2016 10:30 AM<br>
<b>To:</b> PWSCF Forum<br>
<b>Subject:</b> [Pw_forum] analysis of TDDFPT results</font>
<div> </div>
</div><div><div>
<div>
<div dir="ltr"><span style="font-size:12.8px">Dear QE users and developers,</span>
<div><span style="font-size:12.8px"><br>
</span></div>
<div><span style="font-size:12.8px">I've successfully performed a TDDFPT (Lanczos approach) calculation on a system of my interest, and now I would like to analyze the different bands of the resulting spectrum. I would like to ascribe them to chemical (orbital-excitations,
charge-transfer) </span><span style="font-size:12.8px">processes</span><span style="font-size:12.8px"> </span><span style="font-size:12.8px">s</span><span style="font-size:12.8px">uch as I would do when using standard TDDFT codes. </span></div>
<div><span style="font-size:12.8px"><br>
</span></div>
<div><span style="font-size:12.8px">I'd like to know if this is indeed possible and, if so, I'd appreciate some information on how to do it. </span></div>
<div><span style="font-size:12.8px"><br>
</span></div>
<div><span style="font-size:12.8px">All my best,</span></div>
<div><span style="font-size:12.8px">Dr. Sergi Vela, </span><br>
</div>
<div><span style="font-size:12.8px">Laboratoire de Chimie Quantique, Universitè de Strasbourg, France</span></div>
</div>
</div>
</div></div></div>
</div>
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