<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css" style="display:none;"><!-- P {margin-top:0;margin-bottom:0;} --></style>
</head>
<body dir="ltr">
<div id="divtagdefaultwrapper" style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif;" dir="ltr">
<div id="divtagdefaultwrapper" style="font-size: 12pt; color: rgb(0, 0, 0); font-family: Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;" dir="ltr">
<p style="margin-top:0;margin-bottom:0">Dear Nicola and Matteo,</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0">Thank you for your prompt replies and your input on this issue. I'll definitely look into some of these suggested methods. </p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0">I was wondering, however, if there are any more simplified approaches you might consider given that I only have one TM dopant in my supercell. I may very well go beyond this with future calculations, but does the fact
that I only need to control the charge state of one atom in my cell simplify the matter at all?</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0">Thank you again for your time and advice,</p>
<p style="margin-top:0;margin-bottom:0">Eric Suter</p>
<p style="margin-top:0;margin-bottom:0">Dept. of Physics and Astronomy</p>
<p style="margin-top:0;margin-bottom:0">University of Georgia</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
</div>
<span style="font-size: 11pt;">Date: Wed, 26 Jun 2019 20:35:06 +0000</span><br>
<span style="font-size: 11pt;">From: Marzari Nicola <nicola.marzari@epfl.ch></span><br>
<span style="font-size: 11pt;">To: Quantum ESPRESSO users Forum <users@lists.quantum-espresso.org></span><br>
<span style="font-size: 11pt;">Subject: Re: [QE-users] Charges on dopants</span><br>
<span style="font-size: 11pt;">Message-ID: <707E3EF0-BD0F-41F9-81C7-7DEAA5634FE4@epfl.ch></span><br>
<span style="font-size: 11pt;">Content-Type: text/plain; charset="utf-8"</span><br>
<br>
<br>
<span style="font-size: 14.666666984558105px;"><br>
</span><span style="font-size: 11pt;">U can help, but it?s not really the answer - see some of the papers here, and search the literature:</span><br>
<a href="http://theossrv1.epfl.ch/Main/OxidationStates" id="LPlnk289643" class="OWAAutoLink" previewremoved="true" style="font-size: 11pt;">http://theossrv1.epfl.ch/Main/OxidationStates</a><br>
<span style="font-size: 14.666666984558105px;"><br>
</span><span style="font-size: 11pt;">Sent from a tiny keyboard... Contact info:</span><br>
<a href="http://theossrv1.epfl.ch/Main/Contact" id="LPlnk597650" class="OWAAutoLink" previewremoved="true" style="font-size: 11pt;">http://theossrv1.epfl.ch/Main/Contact</a><br>
<br>
<span style="font-size: 14.666666984558105px;"><br>
</span><span style="font-size: 11pt;">Message: 4</span><br>
<span style="font-size: 11pt;">Date: Thu, 27 Jun 2019 10:28:09 +0200</span><br>
<span style="font-size: 11pt;">From: Matteo Cococcioni <matteo.cococcioni@unipv.it></span><br>
<span style="font-size: 11pt;">To: Quantum ESPRESSO users Forum <users@lists.quantum-espresso.org></span><br>
<span style="font-size: 11pt;">Subject: Re: [QE-users] Charges on dopants</span><br>
<span style="font-size: 11pt;">Message-ID:</span><br>
<span style="font-size: 11pt;"> <CAKNx695Pvg5gYog54GMvPRZNNJ60jszhizY9Fzj+D1-U1SR+AA@mail.gmail.com></span><br>
<div style="font-size: 12pt; color: rgb(0, 0, 0); font-family: Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;" dir="ltr">
<div style="color: rgb(0, 0, 0);">
<div class="BodyFragment"><font size="2"><span style="font-size:11pt;">
<div class="PlainText">Content-Type: text/plain; charset="utf-8"</div>
</span></font></div>
</div>
</div>
<div style="font-size: 12pt; color: rgb(0, 0, 0); font-family: Calibri, Helvetica, sans-serif, Helvetica, EmojiFont, "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;" dir="ltr">
<div style="color: rgb(0, 0, 0);">
<div class="BodyFragment"><font size="2"><span style="font-size:11pt;">
<div class="PlainText"><br>
Dear Eric,<br>
<br>
just a couple of quick comments.<br>
If you are already using a large supercell you can probably avoid<br>
supercells (all this would need to be checked to be sure).<br>
Also keep in mind that from version 6.4.1 you can find in the QE<br>
distribution a code called HP (Hubbard parameters) that computes Hubbard U<br>
automatically using DFPT. More details here:<br>
10.1103/PhysRevB.98.085127.<br>
Hope this helps.<br>
Best regards,<br>
<br>
Matteo<br>
<br>
<br>
Il giorno mer 26 giu 2019 alle ore 21:51 Eric Glen Suter <esuter@uga.edu><br>
ha scritto:<br>
<br>
> Hello all,<br>
><br>
><br>
> I'm trying to simulate transition metal dopants in particular charge<br>
> states. I'm more or less familiar with the "tot_charge" tag and how it<br>
> functions. For these transition metals, it seems the extra charge I<br>
> introduce doesn't want to localize on my dopants. I've been looking into<br>
> using the Hubbard U as a way to coerce this extra electron (or hole in some<br>
> cases) to localize on my dopant. I've read up a bit on the literature<br>
> about these types of corrections, but I'd like to know:<br>
><br>
><br>
> 1) Am I on the right track with this line of reasoning? I also take notice<br>
> of the "starting_charge" tag for pw.x. I haven't tried it out, but is that<br>
> a viable way of trying to coax the extra charge to stay on the dopant?<br>
><br>
><br>
> 2) If Hubbard U really is the way to go, is there a way of tuning the U<br>
> parameter that doesn't involve supercells? I'm already working with a<br>
> pretty large cell and I don't have a ton of computational power at my<br>
> disposal.<br>
><br>
><br>
> I understand this is no trivial task, but if anyone has any insight on how<br>
> to model a dopant in a particular charge state, I'd be grateful for a nudge<br>
> in the right direction.<br>
><br>
><br>
> Thank you in advance for any help you might have to offer,<br>
><br>
> Eric Suter<br>
><br>
> Dept. of Physics and Astronomy<br>
><br>
> University of Georgia<br>
> _______________________________________________<br>
> Quantum ESPRESSO is supported by MaX (<a href="http://www.max-centre.eu/quantum-espresso" id="LPlnk203768" class="OWAAutoLink" previewremoved="true">www.max-centre.eu/quantum-espresso</a>)<br>
> users mailing list users@lists.quantum-espresso.org<br>
> <a href="https://lists.quantum-espresso.org/mailman/listinfo/users" id="LPlnk154494" class="OWAAutoLink" previewremoved="true">
https://lists.quantum-espresso.org/mailman/listinfo/users</a><br>
</div>
</span></font></div>
</div>
</div>
</div>
</body>
</html>