<html>
<head>
<meta content="text/html; charset=windows-1252"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
Hi Cyrille,<br>
<br>
Thank you for sharing this! But is it impossible for the method
implemented in pwscf, or for all methods based on DFT?<br>
<br>
best,<br>
Yun-Peng<br>
<br>
<div class="moz-cite-prefix">On 09/13/2015 03:19 AM, BARRETEAU
Cyrille wrote:<br>
</div>
<blockquote
cite="mid:6E80B49CBC3D9F4694B510228B88EE3C264D25E6@E-EXDAGE-A0.extra.cea.fr"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
<div style="direction: ltr;font-family: Times New Roman;color:
#000000;font-size: 10pt;">
Hi Yun-Peng<br>
<br>
If your objective is really to determine quantitatively the
value of the magnetic anisotropy I think that it is an
impossible task to get a precision of 0.01meV!!!<br>
<br>
Already below 0.1meV it is quite delicate but 0.01meV is just
hopeless!<br>
<br>
Good luck<br>
Cyrille<br>
<div><br>
<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 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 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"><font size="2">========================<br>
</font>
<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
style="font-family:Tahoma;
font-size:13px"><b>Cyrille
Barreteau</b><br>
<div
style="font-family:Tahoma;
font-size:13px">
<div
style="font-family:Tahoma;
font-size:13px"><font
size="2"><font
face="Times
New Roman">CEA
Saclay<span
style="background-color:white"></span></font><font
face="Times
New Roman">,
</font><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman">IRAMIS,</font>
SPEC</font></font><font
face="Times
New Roman"><font
face="Times
New Roman"><span
style="background-color:white"> Bat. 771<br>
</span></font>91191
Gif sur Yvette
Cedex<span
style="background-color:white"></span>,
FRANCE
<br>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~</font><br>
<font
face="Times
New Roman">DTU
Nanotech<br>
Ørsteds Plads,
building 345E<br>
DK-2800 Kgs.
Lyngby,
DENMARK</font><br>
<font
face="Times
New Roman"><font
face="Times
New Roman">~~~~~~~~~~~~~~~~~~~~~~~~~~~~</font><br>
</font><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman">+33
1 69 08 29 51
/</font></font></font><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman">+33
6 47 53 66 52
(mobile)
(Fr)</font></font></font>
<br>
</font></font></font><font
face="Times
New Roman">+45
45 25 63 12<font
face="Times
New Roman"><font
face="Times
New Roman">/
+45 28 72
55 18
</font></font></font><font
size="2"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
size="2"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman">(mobile)</font></font></font></font></font></font></font></font></font></font>
<font
face="Times
New Roman">(Dk)</font><br>
<font
face="Times
New Roman">email:
<a class="moz-txt-link-abbreviated" href="mailto:cyrille.barreteau@cea.fr">cyrille.barreteau@cea.fr</a>
/</font><font
face="Times
New Roman"><a class="moz-txt-link-abbreviated" href="mailto:cyrbar@nanotech.dtu.dk">cyrbar@nanotech.dtu.dk</a><br>
Web: <a
moz-do-not-send="true"
href="http://iramis.cea.fr/Pisp/cyrille.barreteau/" tabindex="0"><a class="moz-txt-link-freetext" href="http://iramis.cea.fr/Pisp/cyrille.barreteau/">http://iramis.cea.fr/Pisp/cyrille.barreteau/</a></a></font><font
size="2"><br>
</font><font
size="2">========================</font></div>
</div>
</div>
</div>
<span
style="background-color:white;
font-family:Times New
Roman"><font
color="black"
size="2"><span
dir="ltr"
style="font-size:10pt"><font
size="2"><span
style="font-size:16px"></span></font></span></font></span></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div style="font-family: Times New Roman; color: #000000;
font-size: 16px">
<hr tabindex="-1">
<div style="direction: ltr;" id="divRpF970161"><font
face="Tahoma" color="#000000" size="2"><b>De :</b>
<a class="moz-txt-link-abbreviated" href="mailto:pw_forum-bounces@pwscf.org">pw_forum-bounces@pwscf.org</a> [<a class="moz-txt-link-abbreviated" href="mailto:pw_forum-bounces@pwscf.org">pw_forum-bounces@pwscf.org</a>] de
la part de peter [<a class="moz-txt-link-abbreviated" href="mailto:petercybertron@gmail.com">petercybertron@gmail.com</a>]<br>
<b>Envoyé :</b> samedi 12 septembre 2015 23:33<br>
<b>À :</b> <a class="moz-txt-link-abbreviated" href="mailto:pw_forum@pwscf.org">pw_forum@pwscf.org</a><br>
<b>Objet :</b> Re: [Pw_forum] magnetic anisotropy
calculation using fully-relativistic PPs<br>
</font><br>
</div>
<div>Hi Cyrille,<br>
Since magnetic anisotropy energy is very small (~0.01 meV
per atom in my system), do I need to use higher cutoff
energies to account for such small energy scale?<br>
<br>
best,<br>
Yun-Peng<br>
<br>
<div class="moz-cite-prefix">On 09/12/2015 03:30 PM,
BARRETEAU Cyrille wrote:<br>
</div>
<blockquote type="cite">
<style id="owaParaStyle" type="text/css">
<!--
p
{margin-top:0;
margin-bottom:0}
-->
BODY {direction: ltr;font-family: Times New Roman;color: #000000;font-size: 10pt;}P {margin-top:0;margin-bottom:0;}</style>
<div style="direction:ltr; font-family:Times New Roman;
color:#000000; font-size:10pt">
Dear Yun-Peng,<br>
<br>
>From experience I can just say that calculation
using fully-relativistic PP can be really difficult to
converge and sometimes almost impossible to achieve the
desired accuracy (especially since magneto-crystalline
anisotropy requires very strict convergence thresholds).
You can play with broadening and k points sampling.<br>
<br>
Cyrille<br>
<br>
<div><br>
<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 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 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"><font
size="2">========================<br>
</font>
<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
style="font-family:Tahoma;
font-size:13px"><b>Cyrille Barreteau</b><br>
<div
style="font-family:Tahoma;
font-size:13px">
<div
style="font-family:Tahoma;
font-size:13px"><font size="2"><font face="Times New Roman">CEA Saclay<span
style="background-color:white"></span></font><font face="Times New
Roman">,
</font><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman">IRAMIS,</font>
SPEC</font></font><font
face="Times
New Roman"><font
face="Times
New Roman"><span
style="background-color:white"> Bat. 771<br>
</span></font>91191
Gif sur Yvette
Cedex<span
style="background-color:white"></span>,
FRANCE
<br>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~</font><br>
<font
face="Times
New Roman">DTU
Nanotech<br>
Ørsteds Plads,
building 345E<br>
DK-2800 Kgs.
Lyngby,
DENMARK</font><br>
<font
face="Times
New Roman"><font
face="Times
New Roman">~~~~~~~~~~~~~~~~~~~~~~~~~~~~</font><br>
</font><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman">+33
1 69 08 29 51
/</font></font></font><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman">+33
6 47 53 66 52
(mobile)
(Fr)</font></font></font>
<br>
</font></font></font><font
face="Times
New Roman">+45
45 25 63 12<font
face="Times
New Roman"><font
face="Times
New Roman">/
+45 28 72
55 18 </font></font></font><font
size="2"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
size="2"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman"><font
face="Times
New Roman">(mobile)</font></font></font></font></font></font></font></font></font></font>
<font
face="Times
New Roman">
(Dk)</font><br>
<font
face="Times
New Roman">email:
<a
moz-do-not-send="true"
class="moz-txt-link-abbreviated" href="mailto:cyrille.barreteau@cea.fr"
target="_blank">
<a class="moz-txt-link-abbreviated" href="mailto:cyrille.barreteau@cea.fr">cyrille.barreteau@cea.fr</a></a> /</font><font face="Times New Roman"><a
moz-do-not-send="true"
class="moz-txt-link-abbreviated" href="mailto:cyrbar@nanotech.dtu.dk"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:cyrbar@nanotech.dtu.dk">cyrbar@nanotech.dtu.dk</a></a><br>
Web: <a
moz-do-not-send="true"
href="http://iramis.cea.fr/Pisp/cyrille.barreteau/" tabindex="0"
target="_blank">
</a><a
moz-do-not-send="true"
class="moz-txt-link-freetext"
href="http://iramis.cea.fr/Pisp/cyrille.barreteau/"
target="_blank"><a class="moz-txt-link-freetext" href="http://iramis.cea.fr/Pisp/cyrille.barreteau/">http://iramis.cea.fr/Pisp/cyrille.barreteau/</a></a></font><font
size="2"><br>
</font><font
size="2">========================</font></div>
</div>
</div>
</div>
<span
style="background-color:white;
font-family:Times
New Roman"><font
color="black"
size="2"><span
dir="ltr"
style="font-size:10pt"><font
size="2"><span
style="font-size:16px"></span></font></span></font></span></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div style="font-family:Times New Roman; color:#000000;
font-size:16px">
<hr tabindex="-1">
<div id="divRpF254260" style="direction:ltr"><font
face="Tahoma" color="#000000" size="2"><b>De :</b>
<a moz-do-not-send="true"
class="moz-txt-link-abbreviated"
href="mailto:pw_forum-bounces@pwscf.org"
target="_blank">
pw_forum-bounces@pwscf.org</a> [<a
moz-do-not-send="true"
class="moz-txt-link-abbreviated"
href="mailto:pw_forum-bounces@pwscf.org"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:pw_forum-bounces@pwscf.org">pw_forum-bounces@pwscf.org</a></a>]
de la part de yuewen.fang [<a
moz-do-not-send="true"
class="moz-txt-link-abbreviated"
href="mailto:yuewen.fang@gmail.com"
target="_blank"><a class="moz-txt-link-abbreviated" href="mailto:yuewen.fang@gmail.com">yuewen.fang@gmail.com</a></a>]<br>
<b>Envoyé :</b> samedi 12 septembre 2015 20:42<br>
<b>À :</b> pw_forum<br>
<b>Objet :</b> Re: [Pw_forum] magnetic anisotropy
calculation using fully-relativistic PPs<br>
</font><br>
</div>
<div>
<div style="">Hi, Yun-Peng,
<div><br>
</div>
<div>Thanks for your feedback. It depends on the
matter which you are interested in. I think
this paper (Phys. Rev. B 86, 085135 (2012)) can
help you.
<div><br>
</div>
<div>Bests</div>
<div>Fang<br>
<br>
<hr class="-eMc-email-sig" style="width:101px;
border:0; border-top:1px solid #ccc"
align="left">
<div>
<div style="font-family:Calibri;
font-size:16px;
background-color:rgb(255,255,255)">
<div>
<p class="MsoNormal"><span
style="font-size:10pt" lang="EN-US"><font
face="Georgia">Yue-Wen FANG, PhD
candidate</font></span></p>
</div>
<div>
<p class="MsoNormal"><span
style="font-size:10pt" lang="EN-US"><font
style="word-wrap:break-word"
face="Georgia"><a
moz-do-not-send="true"
href="http://english.ecnu.edu.cn/"
style="word-wrap:break-word"
target="_blank">East China
Normal University</a></font></span></p>
</div>
</div>
<div style="font-family:Calibri;
font-size:16px;
background-color:rgb(255,255,255)">
</div>
</div>
<br>
<div class="gmail_quote"><span dir="ltr"><
<a moz-do-not-send="true"
href="mailto:petercybertron@gmail.com"
target="_blank">
peter</a>> 2015-09-13 02:16:28 wrote:
</span><br>
<blockquote class="gmail_quote"
style="margin:0 0 0 .8ex; border-left:1px
#ccc solid; padding-left:1ex">
<div dir="ltr">
<div>Thank you for your suggestions!<br>
I tried using a small mixing beta
(0.1~0.2), and tried using reasonable
cutoff energies (ecutwfc=50,
ecutrho=500), now the convergence is
much better than before (converged
down to 10^-6 Ry).<br>
Another question is, I can find
ultra-soft and PAW pseudopotentials,
which one is better for spin-orbit
calculations? I am using PBE XC
functional.<br>
<br>
best,<br>
Yun-Peng<br>
<br>
<div class="moz-cite-prefix">On
09/11/2015 08:08 PM, yuewen.fang
wrote:<br>
</div>
<blockquote type="cite">
<div style="">Dear Yun-Peng,
<div><br>
</div>
<div>Plz try to decrease mixing
and perform some convergence
tests for your cutoff energy to
remove the oscillation of the
energy! In addition, this
oscillation could also be caused
by the unreasonable smearing
methods for metals.</div>
<div><br>
</div>
<div>Bests</div>
<div>Fang<br>
<br>
<hr class="-eMc-email-sig"
style="width:101px; border:0;
border-top:1px solid #ccc"
align="left">
<div><a moz-do-not-send="true"
href="http://www.yomail.com/?utm_source=signature"
style="font-size:12pt"
target="_blank">Sent from
YoMail</a></div>
<br>
<div class="gmail_quote"><span
dir="ltr">< <a
moz-do-not-send="true"
href="mailto:petercybertron@gmail.com"
target="_blank">
Peter Cybertron</a>>
2015-09-12 03:10:31 wrote:</span><br>
<blockquote
class="gmail_quote"
style="margin:0 0 0 .8ex;
border-left:1px #ccc solid;
padding-left:1ex">
<div dir="ltr">Hi,<br>
<br>
<br>
I am working in University
of Florida as a postdoc.<br>
I am exploring the
spin-orbital calculations
using pwscf, and I<br>
encounter a very slow
convergence like this:<br>
> grep estimated
scf.out<br>
estimated scf accuracy
< 0.00000004 Ry<br>
... (100 similar lines)<br>
estimated scf accuracy
< 0.00000003 Ry<br>
> grep "total energy"
scf.out<br>
...<br>
total energy =
-3667.91077719 Ry<br>
total energy =
-3667.91078176 Ry<br>
total energy =
-3667.91077642 Ry<br>
total energy =
-3667.91078300 Ry<br>
<br>
<br>
Although the convergence
of total energy seems OK
(down to 0.00001 Ry ~<br>
0.0001 eV = 0.1 meV), I
still feel uncomfortable
since I never encounter<br>
such a problem without
spin-orbit interactions.<br>
<br>
<br>
I downloaded the ultrasoft
and PAW pseudopotentials
from PSLib and I am<br>
using the PBE flavor of XC
functional. The system I
am studying is a two<br>
dimensional magnetic
insulator.<br>
<br>
<br>
The parameters I am using
are:<br>
constrained_magnetization
= 'total direction'<br>
fixed_magnetization(3) =
0.0<br>
lambda = 0.2<br>
ecutwfc = 30.0 ,<br>
ecutrho = 300.0 ,<br>
occupations = 'smearing' ,<br>
degauss = 0.005,<br>
smearing = 'mv' ,<br>
nosym=.true.<br>
mixing_mode = 'local-TF' ,<br>
mixing_beta = 0.9 ,<br>
diagonalization = 'david'
,<br>
<br>
<br>
Which parameter on earth
keep my calculations
non-converged?<br>
<br>
<br>
Best,<br>
Yun-Peng<br>
_______________________________________________<br>
Pw_forum mailing list<br>
<a moz-do-not-send="true"
href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a><br>
<a moz-do-not-send="true"
href="http://pwscf.org/mailman/listinfo/pw_forum" target="_blank">http://pwscf.org/mailman/listinfo/pw_forum</a><br>
<br>
</div>
</blockquote>
</div>
</div>
</div>
<br>
<fieldset
class="mimeAttachmentHeader"
target="_blank"></fieldset>
<br>
<pre> _______________________________________________ Pw_forum mailing list <a moz-do-not-send="true" href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a><a moz-do-not-send="true" href="http://pwscf.org/mailman/listinfo/pw_forum" target="_blank">http://pwscf.org/mailman/listinfo/pw_forum</a></pre>
</blockquote>
<br>
</div>
</div>
</blockquote>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader" target="_blank"></fieldset>
<br>
<pre>_______________________________________________
Pw_forum mailing list
<a moz-do-not-send="true" class="moz-txt-link-abbreviated" href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://pwscf.org/mailman/listinfo/pw_forum" target="_blank">http://pwscf.org/mailman/listinfo/pw_forum</a></pre>
</blockquote>
<br>
</div>
</div>
</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>
</body>
</html>