<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" dir="ltr" style="font-size: 12pt; color: rgb(0, 0, 0); font-family: Calibri, Helvetica, sans-serif, "EmojiFont", "Apple Color Emoji", "Segoe UI Emoji", NotoColorEmoji, "Segoe UI Symbol", "Android Emoji", EmojiSymbols;">
<p>Hi everyone, <br>
</p>
<p><br>
</p>
<p>I am trying to compute the dipole moment in a slab, subject to an external out of plane electric field.
<br>
</p>
<p>From what I understand, there are two main ways of dealing with slabs:</p>
<p>- the dipole correction, which also allows to compute the dipole moment directly.
<br>
</p>
<p>- the truncated Coulomb potential with assume_isolated=2d</p>
<p><br>
</p>
<p>However, I have problems with both of these methods. <br>
</p>
<p><br>
</p>
<p>For the dipole correction, it is claimed in "<span>Density functional perturbation theory for gated two-dimensional heterostructures</span>" (the assume_isolated=2d paper), that linear response has not been developped for dipole correction. Does it mean
that ionic relaxation is wrong with dipole correction ?</p>
<p><br>
</p>
<p>For the truncated Coulomb potential, I do not understand how to set the electric field. I would guess one must not use "tefield", because it is a seesaw potential, while the truncated potential requires a proper potential. I would then like to use "lelfield",
but I feel like this is a whole other framework as well, not designed for slabs but for bulk systems.
<br>
</p>
<p><br>
</p>
<p>So what is the standard for polar slabs with out of plane electric fields, to conduct both ionic relaxation, and dipole moment calculation ?<br>
</p>
<p><br>
</p>
<p>Thanks in advance,<br>
</p>
<p><br>
</p>
<div id="Signature">
<div id="divtagdefaultwrapper" dir="ltr" style="font-size:12pt; color:rgb(0,0,0); font-family:Calibri,Helvetica,sans-serif,"EmojiFont","Apple Color Emoji","Segoe UI Emoji",NotoColorEmoji,"Segoe UI Symbol","Android Emoji",EmojiSymbols">
<p>Best regards, <br>
</p>
<p><br>
</p>
<p>Johan Félisaz<br>
</p>
</div>
</div>
</div>
</body>
</html>