<div dir="ltr"><div>
(Not-so-)Quick and dirty fix: run the atomic code for the Ti pseudopotential on the ground-state electronic configuration; replace the (pseudo-)atomic charge in the file with the one you get for the ground state. Only the starting charge will be affected.</div><div><br></div><div>Paolo<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Aug 27, 2020 at 5:28 PM Colonna Nicola (PSI) <<a href="mailto:nicola.colonna@psi.ch">nicola.colonna@psi.ch</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 id="gmail-m_-7337540741577255985divtagdefaultwrapper" style="font-size:10pt;color:rgb(0,0,0);font-family:Helvetica,Arial,sans-serif" dir="ltr">
<p></p>
<p>Dear QE experts,</p>
<p><br>
</p>
<p> I recently perfomed a scf PBEsol calculation for Tb2Ti2O7 (attached the input file).
<br>
</p>
<p> I would like to plot the difference between the scf charge density and the superposition</p>
<p> of atomic charge. For this purpose I used the PostProcessing tool (plut_num = 9).
<br>
</p>
<p><br>
</p>
<p> I expected the integral of this difference to be ~0 , but I found it to be 4. After a quick check
<br>
</p>
<p> I realized that the Ti pseudopotetial (GBRV-1.4, <span>ti_pbesol_v1.4.uspp.F.UPF</span>) was generated
<br>
</p>
<p> in an ionized configuration with just 1 electron (instead of 2 ) in the 3d orbital. Since there
<br>
</p>
<p> are 4 Ti in the primitive cell, I think this is the reason for the odd result described above.
<br>
</p>
<p><br>
</p>
<p> Indeed during the initialization of a scf calculation for an isolated Ti atom I got:
<br>
</p>
<p> </p>
<div><span style="font-family:Consolas,Courier,monospace,serif,"EmojiFont"">Initial potential from superposition of free atoms</span><br>
<span style="font-family:Consolas,Courier,monospace,serif,"EmojiFont""> Check: negative starting charge= -0.001319</span><br>
<span style="font-family:Consolas,Courier,monospace,serif,"EmojiFont""> starting charge 10.99996, renormalised to 12.00000</span><br>
<br>
</div>
<p> However this renormalization is not done in the PP, and in any case I do not think it would make sense there.
<br>
</p>
<p><br>
</p>
<p> That said, my feeling is that I cannot completely trust the charge density difference.<br>
</p>
<p> Do you have any advise on how to solve this problem (beside changing pseudo)?
<br>
</p>
<p><br>
</p>
<p> Thank you in advance and best regards,</p>
<p><br>
</p>
<p>Nicola Colonna <br>
</p>
<p></p>
<p><br>
</p>
<p><br>
</p>
<div id="gmail-m_-7337540741577255985Signature">
<div style="font-family:Tahoma;font-size:13px">
<div style="font-family:Tahoma;font-size:13px">
<div style="font-family:Tahoma;font-size:13px">
<div style="font-family:Tahoma;font-size:13px">
<div style="font-family:Tahoma;font-size:13px">
<div><font face="Helvetica"><span dir="ltr" id="gmail-m_-7337540741577255985divtagdefaultwrapper" style="font-size:12pt"><span style="font-size:13px"><span style="font-size:13px"><span style="font-size:13px">-----------------------------------------------------</span></span></span></span></font></div>
<font face="Helvetica"></font>
<div><font face="Helvetica"><span dir="ltr" id="gmail-m_-7337540741577255985divtagdefaultwrapper" style="font-size:12pt"><span style="font-size:13px"><span style="font-size:13px"><span style="font-size:13px"><font color="black"><span style="text-transform:none"><font color="black"><font color="black"><span style="font-weight:normal">PAUL
SCHERRER INSTITUT</span></font></font></span></font></span></span></span></span></font></div>
<font face="Helvetica"></font>
<div><font face="Helvetica"><span dir="ltr" id="gmail-m_-7337540741577255985divtagdefaultwrapper" style="font-size:12pt"><span style="font-size:13px"><span style="font-size:13px"><span style="font-size:13px"></span></span></span></span></font></div>
<font face="Helvetica"><span dir="ltr" id="gmail-m_-7337540741577255985divtagdefaultwrapper" style="font-size:12pt"><span style="font-size:13px"><span style="font-size:13px"><span style="font-size:13px">Nicola S. Colonna</span></span></span></span><br>
</font><font style="font-family:Calibri,Helvetica,sans-serif,serif,"EmojiFont"" size="3" face="Calibri,Helvetica,sans-serif" color="black"><span dir="ltr" id="gmail-m_-7337540741577255985divtagdefaultwrapper" style="font-size:12pt"><font style="font-family:Tahoma,serif,"EmojiFont"" size="1" face="Tahoma"><span style="font-size:13px"><font style="font-family:Tahoma,serif,"EmojiFont"" size="1" face="Tahoma"><span style="font-size:13px"><font style="font-family:Tahoma,serif,"EmojiFont"" size="1" face="Tahoma"><span style="font-size:13px"><font face="Helvetica"><span style="text-transform:none"><font color="black"><font color="black"><font style="font-family:Helvetica,serif,"EmojiFont"" face="Helvetica" color="black"><span style="font-weight:normal"><font face="Helvetica"></font>
<div style="text-indent:0px"><font face="Helvetica">WHGA/150<br>
CH-5232 Villigen-PSI</font></div>
</span></font></font></font></span></font></span></font></span></font></span></font></span></font></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
_______________________________________________<br>
Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu/quantum-espresso" rel="noreferrer" target="_blank">www.max-centre.eu/quantum-espresso</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://lists.quantum-espresso.org/mailman/listinfo/users" rel="noreferrer" target="_blank">https://lists.quantum-espresso.org/mailman/listinfo/users</a></blockquote></div><br clear="all"><br>-- <br><div dir="ltr" class="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>