<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p>Dear Anindya Bose,</p>
<p>it seems that you need to go back to the basics and try to
understand some things.<br>
And if someone of your group would help, it would be much better
also for you.<br>
+ Sometimes one just needs to read the publications corresponding
to a method.<br>
</p>
<p>The cutoff for the wave functions has nothing to do with whether
you want to simulate<br>
a monolayer or a bulk system - the cutoff depends on the
pseudopotential you're using.</p>
<p>Whether to use esm_bc or just adding vacuum cannot be answered
without knowing<br>
what you want to do afterwards. Both methods should give the same
result if you're<br>
calculating an uncharged system - in fact, the esm method also
needs to use some<br>
vacuum to avoid interactions between the repeated images (via
overlapping wave<br>
functions). Read the paper by Otani/Sugino in order to understand
the method:</p>
<p><a class="moz-txt-link-freetext" href="http://journals.aps.org/prb/abstract/10.1103/PhysRevB.73.115407">http://journals.aps.org/prb/abstract/10.1103/PhysRevB.73.115407</a><br>
</p>
<p>Without knowing what you mean with "I am getting convergence
problems" we cannot<br>
help.</p>
<p>Thomas<br>
</p>
<br>
<div class="moz-cite-prefix">On 03/09/2017 08:32 AM, Anindya Bose
wrote:<br>
</div>
<blockquote
cite="mid:CAJXtw3wFzpshiF71tjs_-aSb2otbEL+giZVTjECSWi5+3E3_HA@mail.gmail.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
<div dir="ltr">
<div>
<div>
<div>Dear Sir,<br>
</div>
To simulate a isolated Monolayer WSe2
structure(nat=3,ntyp=2) , should I choose the value of
ecutwfc very high(=70, ecutrho=4*ecutwfc) and should I use
esm_bc to add vacuum or should I increase this using stretch
cell method.Actually I am getting convergence
problems.Please tell me how to sort this out.<br>
<br>
</div>
Thanks and regards,<br>
</div>
Anindya Bose</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
Pw_forum mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a>
<a class="moz-txt-link-freetext" href="http://pwscf.org/mailman/listinfo/pw_forum">http://pwscf.org/mailman/listinfo/pw_forum</a></pre>
</blockquote>
<br>
<pre class="moz-signature" cols="72">--
Dr. rer. nat. Thomas Brumme
Max Planck Institute for the Structure and Dynamics of Matter
Luruper Chaussee 149
22761 Hamburg
Tel: +49 (0)40 8998 6557
email: <a class="moz-txt-link-abbreviated" href="mailto:Thomas.Brumme@mpsd.mpg.de">Thomas.Brumme@mpsd.mpg.de</a>
</pre>
</body>
</html>