<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Hello,</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
My system is an organic molecular crystal (atoms C, H, N, O). The cutoff is chosen so there is 2 meV/atom error for SCF energy. The k-point grid 3x2x3 (off-centered) yields perfectly converged SCF energy. But to get faster with the vc-relax, I lowered it to
2x1x2 (off-centered), which introduces an error of only -0.1 meV/atom. I don't know if this is the reason why vc-relax density and pressure oscillate without converging.<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
I'm currently running v-relax with 3x2x3 grid... waiting for the result (10x slower)...</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Thank you,</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Xavier<br>
</div>
<div id="appendonsend"></div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> users <users-bounces@lists.quantum-espresso.org> on behalf of Paolo Giannozzi <p.giannozzi@gmail.com><br>
<b>Sent:</b> Monday, January 25, 2021 9:38 AM<br>
<b>To:</b> Quantum ESPRESSO users Forum <users@lists.quantum-espresso.org><br>
<b>Subject:</b> Re: [QE-users] vc-relax with PBE0 not converging</font>
<div> </div>
</div>
<div>
<div dir="ltr">
<div>Maybe the same problem reported here?</div>
<div> <a href="https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgitlab.com%2FQEF%2Fq-e%2F-%2Fissues%2F204&data=04%7C01%7Cxavbdlt%40uic.edu%7C3fdf0cc0f8bd4cd43e8308d8c14769ce%7Ce202cd477a564baa99e3e3b71a7c77dd%7C0%7C0%7C637471859758045446%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=QCUVoTzncfJfau7FM88IUZSHHmCHJf9wUl50miJJ4W4%3D&reserved=0" originalsrc="https://gitlab.com/QEF/q-e/-/issues/204" shash="bkX76AW8GvyWmULgV9fREiy0f0pQ0TaX2OH7CvftAGX11fdpeE/kr2d5RjGAU11+jFr5huZXwa6A+vfTOHB1Qz9MEBehhuSTIRsYiu6H1VnisoF4hP2NgrsvZd9CV8dZc8FEf0C8CeL2iu4wwGhTZgPvHm2M7uLBuvdMMvDeWDs=">
https://gitlab.com/QEF/q-e/-/issues/204</a></div>
<div>Paolo<br>
</div>
</div>
<br>
<div class="x_gmail_quote">
<div dir="ltr" class="x_gmail_attr">On Mon, Jan 25, 2021 at 4:19 PM Bidault, Xavier <<a href="mailto:xavbdlt@uic.edu">xavbdlt@uic.edu</a>> wrote:<br>
</div>
<blockquote class="x_gmail_quote" style="margin:0px 0px 0px 0.8ex; border-left:1px solid rgb(204,204,204); padding-left:1ex">
<div dir="ltr">
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Hello,</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
I have a molecular crystal (1 unit cell = 56 atoms). I use SG15 ONCV 1.2 pseudopotential and Grimme D2 correction.<br>
</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Using vc-relax with PBE, the structure converges, no problem.</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
But with PBE0, density and pressure oscillate without dampening (see figure below - Pressure remains negative, and not close to zero). Is there any particular strategy with PBE0?</div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<ul>
<li><span>vc-relax with PBE and then starting from the result and use PBE0?</span></li><li><span>relax with PBE0 and then vc-relax?</span></li><li><span>any simulation parameter to change (ion dynamics and/or cell dynamics - currently BFGS)?</span></li><li><span>any strategy with PBE0?</span></li></ul>
<div></div>
<div><img size="28643" style="max-width:100%" data-outlook-trace="F:1|T:1" src="cid:1773a31d564cb971f161"><br>
</div>
<div>Thank you,</div>
<div>Xavier<br>
</div>
<div><br>
</div>
</div>
</div>
_______________________________________________<br>
Quantum ESPRESSO is supported by MaX (<a href="https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.max-centre.eu%2F&data=04%7C01%7Cxavbdlt%40uic.edu%7C3fdf0cc0f8bd4cd43e8308d8c14769ce%7Ce202cd477a564baa99e3e3b71a7c77dd%7C0%7C0%7C637471859758045446%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=sd3E5%2FhytwHgry%2Bvhoi4xrI%2F2AwuoSy5%2FOnqdAivFhs%3D&reserved=0" originalsrc="http://www.max-centre.eu/" shash="RPjjCMkgsl6PuKg05R1hew1J08RMy/FETu1Vq+G58J33yAwpkGzef4dtmhSSAudSZZrjexGgQEoDiWMRqlORFAQvv2FZYqlXsgJ87Y3l4+LNvZfYuzNca/K3qUYZQgXNmb0eywEhM++6+qacf/wDAg2cgHk1h4Y/b1DmH+j+8AU=" rel="noreferrer" target="_blank">www.max-centre.eu</a>)<br>
users mailing list <a href="mailto:users@lists.quantum-espresso.org" target="_blank">
users@lists.quantum-espresso.org</a><br>
<a href="https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.quantum-espresso.org%2Fmailman%2Flistinfo%2Fusers&data=04%7C01%7Cxavbdlt%40uic.edu%7C3fdf0cc0f8bd4cd43e8308d8c14769ce%7Ce202cd477a564baa99e3e3b71a7c77dd%7C0%7C0%7C637471859758055404%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C2000&sdata=rLgz1kcGcloPgRTtOcAQJcRXdnlFNRtxNyn5cLZt9vE%3D&reserved=0" originalsrc="https://lists.quantum-espresso.org/mailman/listinfo/users" shash="zyfHdHz70G+KXHtfIHgrm7syfhhTb98WxBvAPqFQEBW/Cqn9wFEFnwYqNNV/xh9FfBPKrO9VPPycW0mfDAk/g1wCIyYjqfz16VmKQcZYk7D8GFT2N3JGgkikCIJ/3eME2yzALxQKz7BDY0bRn5vLbPDOFttBHsLTXY/CHopixXk=" rel="noreferrer" target="_blank">https://lists.quantum-espresso.org/mailman/listinfo/users</a></blockquote>
</div>
<br clear="all">
<br>
-- <br>
<div dir="ltr" class="x_gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,<br>
Univ. Udine, via delle Scienze 206, 33100 Udine, Italy<br>
Phone +39-0432-558216, fax +39-0432-558222<br>
<br>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>