<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Besides, intermolecular distances in a molecular crystal sensitively depend on the XC functional, all of which have a hard time properly accounting for dispersion forces (some of them a worse time than others). SB<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 2 Dec 2020, at 19:38, Claudio A. Perottoni <<a href="mailto:caperott@gmail.com" class="">caperott@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">Dear Corrado,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small"><br class=""></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">The ecutwfc in your input file seems a bit small. You may try using <a href="https://www.materialscloud.org/work/tools/qeinputgenerator" class="">https://www.materialscloud.org/work/tools/qeinputgenerator</a> to generate an input file for optimizing the crystal structure of your compound.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">Best regards,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small">Claudio</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif;font-size:small"><br class=""></div></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Dec 2, 2020 at 3:15 PM Cuocci Corrado <<a href="mailto:corrado.cuocci@gmail.com" class="">corrado.cuocci@gmail.com</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">I have determined the crystal structure of new organic compound from <br class="">
X-ray powder diffraction data.<br class="">
<br class="">
First of all, I used quantum espresso to validate my new structure in a <br class="">
'relax' calculation obtaining a result in a good agreement with the <br class="">
experimental structure.<br class="">
<br class="">
In a second step I tried to perform a 'vc-relax' but in this case the <br class="">
result seems chemically unreasonable: I observed a large variation of <br class="">
the cell parameters, final density too high for this type of compound, <br class="">
short intermolecular distances.<br class="">
Input and output files can be downloaded from:<br class="">
<a href="https://cloud.ba.cnr.it/index.php/s/5RmA7MqA9gJeRdx/download" rel="noreferrer" target="_blank" class="">https://cloud.ba.cnr.it/index.php/s/5RmA7MqA9gJeRdx/download</a><br class="">
<a href="https://cloud.ba.cnr.it/index.php/s/qmnAwM5JeqDnHdG/download" rel="noreferrer" target="_blank" class="">https://cloud.ba.cnr.it/index.php/s/qmnAwM5JeqDnHdG/download</a><br class="">
<br class="">
My experience in the use of the program is limited and I suspect I have <br class="">
made some mistakes.<br class="">
Do you have any suggestions to improve the calculation?<br class="">
<br class="">
Thanks a lot.<br class="">
Corrado<br class="">
-- <br class="">
============================================<br class="">
Cuocci Corrado<br class="">
Istituto di Cristallografia - CNR<br class="">
Via G. Amendola,122/o<br class="">
70126 Bari (Italy)<br class="">
tel: +390805929161<br class="">
fax:+390805929170<br class="">
<a href="mailto:corrado.cuocci@ic.cnr.it" target="_blank" class="">corrado.cuocci@ic.cnr.it</a><br class="">
============================================<br class="">
_______________________________________________<br class="">
Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu/" rel="noreferrer" target="_blank" class="">www.max-centre.eu</a>)<br class="">
users mailing list <a href="mailto:users@lists.quantum-espresso.org" target="_blank" class="">users@lists.quantum-espresso.org</a><br class="">
<a href="https://lists.quantum-espresso.org/mailman/listinfo/users" rel="noreferrer" target="_blank" class="">https://lists.quantum-espresso.org/mailman/listinfo/users</a><br class="">
</blockquote></div><br clear="all" class=""><div class=""><br class=""></div>-- <br class=""><div dir="ltr" class="gmail_signature"><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><pre style="white-space:pre-wrap" class=""><font size="2" face="georgia, serif" class=""><b class="">Claudio A. Perottoni</b></font></pre><pre style="white-space:pre-wrap" class=""><font size="2" style="font-family:georgia,serif" class="">Universidade de Caxias do Sul
95070-560 Caxias do Sul - RS - Brazil</font><font face="georgia, serif" class="">
</font><a href="http://www.researcherid.com/rid/B-8409-2008" style="color:rgb(17,85,204)" target="_blank" class=""><font face="arial, helvetica, sans-serif" class="">http://www.researcherid.com/rid/B-8409-2008</font></a></pre></div></div></div></div></div></div></div></div></div></div></div></div></div></div>
_______________________________________________<br class="">Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu" class="">www.max-centre.eu</a>)<br class="">users mailing list <a href="mailto:users@lists.quantum-espresso.org" class="">users@lists.quantum-espresso.org</a><br class=""><a href="https://lists.quantum-espresso.org/mailman/listinfo/users" class="">https://lists.quantum-espresso.org/mailman/listinfo/users</a></div></blockquote></div><br class=""></body></html>