<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>Hi,</p>
<p>What I could verify is that, in a simple test on rutile TiO2, I
obtain the same total energy (to within 10**(-7) Ry) with any of
these lines in the input file:</p>
<p>input_dft='sla+pw+tb09+tb09'</p>
<p>input_dft='pw+pbc+tb09+tb09'</p>
<p>input_dft="noc+nogc+tb09+tb09"<br>
</p>
<p>The first case is the one specified in the Modules/funct.f90 file
as equivalent to input_dft='tb09', the second one corresponds to
having gga correlation, the last one, to using no correlation at
all. One can understand this since the said file contains these
lines:</p>
<p> ! special case : TB09 meta-GGA Exc<br>
else IF ('TB09'.EQ. TRIM(dftout) ) THEN<br>
dft_defined = set_dft_values(0,0,0,0,0,3)</p>
<p> I think that since the original mBJ functional was defined as
including LDA correlation, this should be changed. Preferably, by
allowing the user to specify the type of correlation (s)he
desires. I wonder if just suppressing in the said file the three
lines mentioned above would be enough.</p>
<p>Regards,<br>
</p>
JC Conesa<br>
<br>
<div class="moz-cite-prefix">El 05/05/2018 a las 10:44, Paolo
Giannozzi escribió:<br>
</div>
<blockquote type="cite"
cite="mid:CAPMgbCsJrRANMeiVrN+jcFfb=dDbs9o7dsruQ-XiSotcPrD+cA@mail.gmail.com">
<div dir="ltr">
<div>I don't think it is possible right now to use any meta-GGA
with exchange/correlations/gradient corrections that differ
from those assumed in the original definition of the meta-GGA
functional. Meta-GGA follow a different path from all other XC
functionals. I hope to manage sooner or later to clean up the
meta-GGA mess, but cannot guarantee anything.<br>
<br>
</div>
Paolo<br>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Fri, May 4, 2018 at 6:33 PM, José C.
Conesa <span dir="ltr"><<a
href="mailto:jcconesa@icp.csic.es" target="_blank"
moz-do-not-send="true">jcconesa@icp.csic.es</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<p><font face="Helvetica, Arial, sans-serif">Hi,<br>
</font></p>
<p><font face="Helvetica, Arial, sans-serif">Does this
mean that it is not possible to combine tb09 with any
correlation contribution?</font></p>
<p><font face="Helvetica, Arial, sans-serif">José Carlos</font><br>
</p>
<div>
<div class="h5"> <br>
<div class="m_3291306830783023308moz-cite-prefix">El
04/05/2018 a las 17:41, Paolo Giannozzi escribió:<br>
</div>
<blockquote type="cite">
<div dir="ltr">I think that with meta-GGA what is
written in the first two fields is just ignored <br>
<br>
Paolo<br>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Fri, May 4, 2018 at
5:39 PM, José C. Conesa <span dir="ltr"><<a
href="mailto:jcconesa@icp.csic.es"
target="_blank" moz-do-not-send="true">jcconesa@icp.csic.es</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0
0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<p><font face="Helvetica, Arial, sans-serif">Dear
QE developers,</font></p>
<p>I wish to use in Quantum Espresso the
tb09 potential-only meta-GGA functional
(from Tran & Blaha, PRL 102, 2009,
226401) which is available in libxc. I
downloaded the libxc library and compiled
successfully qe-6.2.1 with it. Then I see
in Modules/funct.f90 that the instruction
to use this functional is equivalent to
specifying <br>
</p>
<p>input_dft="sla+pw+tb09+tb09"</p>
<p>But as far as I know, the tb09 functional
gives only the exchange part, and gives it
in full (not as a correction to another
expression for the exchange), while sla is
a LDA exchange form (and pw a LDA
correlation form). Should one conclude
that exchange is being introduced twice?
And, is a gradient correction to the
correlation term not included? From these
considerations, I would have thought that
using something like <br>
</p>
<p>input_dft="pw+pbc+tb09+tb09"</p>
<p>(where I hope that the tb09 exchange
functional is not included twice), i.e.
the correlation part of PBE plus the Tran
& Blaha exchange functional, would be
the proper way to proceed.</p>
<p>Can you please comment on this?</p>
<p>I also would add that it would be good to
be able to adjust the A and B parameters
of the tb09 functional. This has been
proposed in (Koller, Tran & Blaha, PRB
85, 2012, 155109) to obtain better
bandgaps in certain families of
semiconductors.</p>
<p>All the best,<span
class="m_3291306830783023308HOEnZb"><font
color="#888888"><br>
</font></span></p>
<span class="m_3291306830783023308HOEnZb"><font
color="#888888">
<pre class="m_3291306830783023308m_5099655024476259839moz-signature" cols="72">--
José C. Conesa
Instituto de Catálisis y Petroleoquímica, CSIC
Marie Curie 2, Cantoblanco
28049 Madrid, Spain
Tel. (+34)915854766</pre>
<div
id="m_3291306830783023308m_5099655024476259839DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br>
<table style="border-top:1px solid
#d3d4de">
<tbody>
<tr>
<td
style="width:55px;padding-top:18px"><a
href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient"
target="_blank"
moz-do-not-send="true"><img
src="https://ipmcdn.avast.com/images/icons/icon-envelope-tick-round-orange-animated-no-repeat-v1.gif"
alt=""
style="width:46px;height:29px"
moz-do-not-send="true"
height="29" width="46"></a></td>
<td
style="width:470px;padding-top:17px;color:#41424e;font-size:13px;font-family:Arial,Helvetica,sans-serif;line-height:18px">Libre
de virus. <a
href="https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient"
style="color:#4453ea"
target="_blank"
moz-do-not-send="true">www.avast.com</a>
</td>
</tr>
</tbody>
</table>
<a
href="#m_3291306830783023308_m_5099655024476259839_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"
width="1" height="1"
moz-do-not-send="true"> </a></div>
</font></span></div>
<br>
______________________________<wbr>_________________<br>
users mailing list<br>
<a
href="mailto:users@lists.quantum-espresso.org"
target="_blank" moz-do-not-send="true">users@lists.quantum-espresso.o<wbr>rg</a><br>
<a
href="https://lists.quantum-espresso.org/mailman/listinfo/users"
rel="noreferrer" target="_blank"
moz-do-not-send="true">https://lists.quantum-espresso<wbr>.org/mailman/listinfo/users</a><br>
</blockquote>
</div>
<br>
<br clear="all">
<br>
-- <br>
<div class="m_3291306830783023308gmail_signature"
data-smartmail="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>Paolo Giannozzi, Dip. Scienze
Matematiche Informatiche e Fisiche,<br>
Univ. <a
href="https://maps.google.com/?q=Udine,+via+delle+Scienze+208,+33100+Udine,+Italy&entry=gmail&source=g"
moz-do-not-send="true">Udine, via
delle Scienze 208, 33100 Udine, Italy</a><br>
Phone +39-0432-558216, fax
+39-0432-558222<br>
<br>
</div>
</div>
</div>
</div>
</div>
</div>
<br>
<fieldset
class="m_3291306830783023308mimeAttachmentHeader"></fieldset>
<br>
<pre>______________________________<wbr>_________________
users mailing list
<a class="m_3291306830783023308moz-txt-link-abbreviated" href="mailto:users@lists.quantum-espresso.org" target="_blank" moz-do-not-send="true">users@lists.quantum-espresso.<wbr>org</a>
<a class="m_3291306830783023308moz-txt-link-freetext" href="https://lists.quantum-espresso.org/mailman/listinfo/users" target="_blank" moz-do-not-send="true">https://lists.quantum-<wbr>espresso.org/mailman/listinfo/<wbr>users</a></pre>
</blockquote>
<br>
<pre class="m_3291306830783023308moz-signature" cols="72">--
José C. Conesa
Instituto de Catálisis y Petroleoquímica, CSIC
Marie Curie 2, Cantoblanco
28049 Madrid, Spain
Tel. (+34)915854766</pre>
</div>
</div>
</div>
</blockquote>
</div>
<br>
<br clear="all">
<br>
-- <br>
<div class="gmail_signature" data-smartmail="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>Paolo Giannozzi, Dip. Scienze Matematiche
Informatiche e Fisiche,<br>
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy<br>
Phone +39-0432-558216, fax +39-0432-558222<br>
<br>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
José C. Conesa
Instituto de Catálisis y Petroleoquímica, CSIC
Marie Curie 2, Madrid, Spain
<a class="moz-txt-link-abbreviated" href="http://www.icp.csic.es">www.icp.csic.es</a>
Tel. (+34)915854766
</pre>
</body>
</html>