<div dir="ltr"><div>Dear Rekha,</div><div><br></div><div>You do not need to generate the vdW table. It is on-the-fly in new versions of quantum ESPRESSO. To the best of my knowledge, you should use revPBE pseudo-potentials for vdW-<span style="font-family:"Helvetica Neue",Arial,sans-serif;font-size:15px">optB86b</span> functional. Check the paper on this functional. However, I always use PBE ones. but, remember not to use LDA + vdW (semi-empirical or ab-initio) for considering long-range interactions.</div><div><br></div><div>see for example:</div><div><a href="https://journals.aps.org/prb/abstract/10.1103/PhysRevB.83.195131">https://journals.aps.org/prb/abstract/10.1103/PhysRevB.83.195131</a></div><div><a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.91.126402">https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.91.126402</a></div><div><br></div><div><br></div><div>Best,</div><div><br></div><div>Mohammad</div><div><br></div><div>ShirazU<br></div>
</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Sep 16, 2020 at 10:34 PM rekha sharma <<a href="mailto:rekha1997jpr@gmail.com">rekha1997jpr@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Dear Sir,</div><div>This is in connection with my previous email (how to use <span style="font-family:"Helvetica Neue",Arial,sans-serif;font-size:15px">optB86b).</span></div><div><span style="font-family:"Helvetica Neue",Arial,sans-serif;font-size:15px"><br></span></div><div><span style="font-family:"Helvetica Neue",Arial,sans-serif;font-size:15px">Version of QE is 6.5.</span></div><div><span style="font-family:"Helvetica Neue",Arial,sans-serif;font-size:15px"><br></span></div><div><font face="Helvetica Neue, Arial, sans-serif"><span style="font-size:15px">After a detailed search I found that I need to generate </span></font><span style="font-family:sans-serif;font-size:14px">vdW_kernel_table</span><font face="Helvetica Neue, Arial, sans-serif"><span style="font-size:15px"> using </span></font></div><div><pre style="white-space:pre-wrap;color:rgb(0,0,0)"><i> generate_vdw_kernel_table.x</i></pre></div>and then keep that table in the directory where we keep our PPs and then we can use regular PPs with <div><div><br></div><div>! vdw_corr='Grimme-D3', (optB86b with vdw_corr did not work so I removed it)<br></div> input_dft='vdW-DF-ob86',<br><div><br></div><div>But I am not getting <i style="color:rgb(0,0,0);white-space:pre-wrap"> generate_vdw_kernel_table.x on my system.</i></div><div>How can I get it?</div><div> Do I need to install some other libraries for it?</div><div><br></div><div>Please help me.</div><div><br></div><div>Thank you very much.</div><div><br></div><div>Rekha</div><div><br></div><div><br></div><div><br></div><div> <br></div><div><br></div><div><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Sep 16, 2020 at 12:22 PM rekha sharma <<a href="mailto:rekha1997jpr@gmail.com" target="_blank">rekha1997jpr@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Dear Users,</div><div>I want to simulate a carbon based layered materials where I want to use optB86b functional.</div><div><br></div><div>I use:</div><div><br></div><div>! vdw_corr='Grimme-D3', (optB86b with vdw_corr did not work so I removed it)<br></div> input_dft='vdW-DF-ob86',<br><div><br></div><div>Can someone please confirm whether the regular Pseudopotentials available on Quantum Espresso Web-Page works or for optB86b functional I need some other PPs?</div><div><br></div><div><br></div><div>Thank you very much,</div><div><br></div><div>Best regards</div><div>Rekha</div><div><br></div></div></div></div>
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