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<p>In WIEN2k the total energy does not go to a minimum during scf,
but even more negative values can occur during scf.</p>
<p>It would be interesting to know if this is the same in other
codes or not.</p>
<p>grep :ene 5_default.scf<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.61390837
<====<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.50214748<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.50211022<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.50200377<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.50748913<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.51004385<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.51010217<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.51073277<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.51072611<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.51066136<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.51216359
<====<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.51034576<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.50887600<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.50840575<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.50840424<br>
:ENE : ********** TOTAL ENERGY IN Ry = -14900.50840424
<====<br>
<br>
</p>
<div class="moz-cite-prefix">Am 31.01.2022 um 15:23 schrieb Laurence
Marks:<br>
</div>
<blockquote type="cite"
cite="mid:CANkSMZByvmPd_km57FhM=kQ=knvPFKsRUPt458QryxMBv76+sA@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr">
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:#000000">In Wien2k
the total energy is calculated in part from the current
density, in part from the density of the orbitals that solve
the KS equation. As such it is not a true variational energy
except when the density is converged. [1]</div>
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:#000000"><br>
</div>
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:#000000">For other
dft codes (not wavefunction codes [2]), is it the same, e.g.
Vasp, QE, ab-init? Responses welcome, either via the list of
directly.</div>
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:#000000"><br>
</div>
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:#000000">[1] There
are technically ways one could calculate some form of
variational energy, but it would require extra steps and to my
knowledge has never looked useful so is not in the code.</div>
<div class="gmail_default"
style="font-family:verdana,sans-serif;color:#000000">[2] In
wavefunction codes where one varies the occupancy the energy
is typically variational I think.</div>
<div><br>
</div>
-- <br>
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">
<div dir="ltr">Professor Laurence Marks<br>
Department of Materials Science and Engineering<br>
Northwestern University<br>
<a href="http://www.numis.northwestern.edu/" target="_blank"
moz-do-not-send="true">www.numis.northwestern.edu</a>
<div>"Research is to see what everybody else has seen, and
to think what nobody else has thought" Albert <span
style="font-family:Arial,Helvetica,sans-serif;font-size:12.8px">Szent-</span><span
style="font-family:Arial,Helvetica,sans-serif;font-size:small;color:rgb(34,34,34)">Györgyi</span></div>
</div>
</div>
</div>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
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</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
-----------------------------------------------------------------------
Peter Blaha, Inst. f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-158801165300
Email: <a class="moz-txt-link-abbreviated" href="mailto:peter.blaha@tuwien.ac.at">peter.blaha@tuwien.ac.at</a>
WWW: <a class="moz-txt-link-freetext" href="http://www.imc.tuwien.ac.at">http://www.imc.tuwien.ac.at</a> WIEN2k: <a class="moz-txt-link-freetext" href="http://www.wien2k.at">http://www.wien2k.at</a>
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