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<p class="p1">Dear Elie Moujaes</p>
<p class="p2"><br></p><p class="p2">Sorry for posting again. </p><p class="p2"><br></p>
<p class="p1">>(1) is changing the mesh in the DOS program means decreasing DeltaE?</p>
<p class="p2"><br></p>
<p class="p1">I'm sorry I wrote a little confusing description. </p>
<p class="p1">I meant to say that, in my previous posting, the checking of the convergence in Fermi-energy with respect to the mesh of k-points in nscf calculation". </p>
<p class="p1">You will/should observe the convergence as the increase of k-mesh. After you get the sufficient condition in the k-mesh, you will obtain more reliable value of Fermi-energy in DOS calculation. </p>
<p class="p1">(note that, in my opinion, if you want to get the precise value as much as possible, the decision of the value of Fermi-energy should be done by counting number of electrons with looking output file obtained by DOS calculation (by the checking of integrated DOS). </p>
<p class="p2"> </p>
<p class="p2"><br></p>
<p class="p1">>(2) Concerning the convergence against smearing, does this mean that one has to decrease degauss (mine is degauss=0.01) to get better results?</p>
<p class="p2"><br></p>
<p class="p1">If you already checked the convergence of, for example, the total energy in your system against change of degauss ( and the number of k-points), I think it is no problem. </p><p class="p1">( Note: Your "degauss =0.01" is about 0.13 eV which value is within the error of the value of Fermi-energy which you reported. So I'm a little worried about the value of degauss. Did you check the change of Fermi-energy against the "degauss" ?</p>
<p class="p2"><br></p>
<p class="p1"><br></p><p class="p1">Perhaps, my comments to you are incorrect ( if so, it lead the waste of time in your life, I want to say very sorry for confusing you, in advance). </p>
<p class="p1"><br></p><p class="p1"><br></p><p class="p1"><br></p><p class="p1"><br></p><p class="p1">I hope you can get better result. </p>
<p class="p2"><br></p>
<p class="p2"><br></p>
<p class="p2"><br></p>
<p class="p1">Haruhiko Dekura</p>
<p class="p2"><br></p>
<p class="p2"><br></p>
<p class="p3">========================================</p>
<p class="p3">Haruhiko Dekura</p>
<p class="p4"><br></p>
<p class="p3">Postdoctoral Fellow</p>
<p class="p4"><br></p>
<p class="p3">Senior Research Fellow Center, Ehime University, 2?5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan</p>
<p class="p3">=====================================</p></div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<br>
<br>
Thank you very much for your help. I have just got some few more questions:<br>
<br>
(1) is changing the mesh in the DOS program means decreasing DeltaE?<br>
<br>
(2) Concerning the convergence against smearing, does this mean that one has to decrease degauss (mine is degauss=0.01) to get better results?<br>
<br>
You will find below a part of the bands input file.<br>
<br>
&control<br>
prefix='GBdensity',<br>
calculation='bands',<br>
restart_mode='from_scratch',<br>
pseudo_dir = '/exp/home/caiapo/emoujaes/espresso/espresso-4.1.3/pseudo/',<br>
outdir='/exp/home/caiapo/emoujaes/espresso/Moujaes-Results/',<br>
<br>
/<br>
&system<br>
ibrav= 0, celldm(1) =1.889725989, nat=60, ntyp= 1, ecutwfc =40.0, ecutrho = 160.D0, occupations='smearing', smearing='mp', degauss=0.01<br>
/<br>
&electrons<br>
conv_thr=1.D-5,<br>
mixing_beta=0.1D0,<br>
<br>
/<br>
<br>
CELL_PARAMETERS (alat)<br>
24.064488464 0.000772242 0.000000000<br>
-0.000547177 6.503051170 0.000000000<br>
0.000000000 0.000000000 8.470514812<br>
<br>
<br>
ATOMIC_SPECIES<br>
C 12.0107 C.pz-rrkjus.UPF<br>
<br>
ATOMIC_POSITIONS (angstrom)<br>
C -11.330758616 -3.527803203 0.000000000<br>
C -10.659793092 -1.160339161 0.000000000<br>
C -12.039843315 -7.112619698 0.000000000<br>
C -12.041158182 -5.732701936 0.000000000<br>
C -10.941089654 -4.881442842 0.000000000<br>
C -10.331417950 -2.543878336 0.000000000<br>
C -8.972994221 -3.016349126 0.000000000<br>
C -8.181174559 -0.722870888 0.000000000<br>
C -9.522448653 -6.774832629 0.000000000<br>
C -9.676361200 -5.364937582 0.000000000<br>
C -8.645931928 -4.406311082 0.000000000<br>
<br>
..........<br>
...........<br>
<br>
<br>
Thanks again<br>
<br>
Elie Moujaes<br>
University of Nottingham<br>
NG7 2RD<br>
UK<br>
<br>
<br>
<br>
<br>
<br>
Date: Wed, 26 Jan 2011 01:42:39 +0900<br>
From: <a href="mailto:adadadad3018@gmail.com">adadadad3018@gmail.com</a><br>
To: <a href="mailto:pw_forum@pwscf.org">pw_forum@pwscf.org</a><br>
CC: <a href="mailto:dekura@sci.ehime-u.ac.jp">dekura@sci.ehime-u.ac.jp</a><br>
Subject: Re: [Pw_forum] 60 atom Grain boundary... (Elie Moujaes)<br>
<br>
<br>
<br>
<br>
<br>
Dear Elie Moujaes<br>
<br>
<br>
<br>
<br>
Do you mean that your calculated Fermi-energy in C60 system is not located at which the DOS becomes zero even though you got the reasonable band structure.<br>
<br>
<br>
If so, I recommend a check for the convergence of Fermi-energy.<br>
<br>
For example,<br>
<br>
<br>
please check the energy convergence against<br>
<br>
<br>
(1) increase of the number of k-points in nscf calculation, after you confirm that the KS energy spectrum is converged sufficiently in SCF calculation (and also should check the convergence against the smearing width)<br>
<br>
<br>
(2) change in the mesh in DOS calculation.<br>
<br>
<br>
<br>
<br>
May be you will get more reliable and better result.<br>
<br>
<br>
<br>
<br>
Hope this helps.<br>
<br>
<br>
<br>
<br>
Best Regards.<br>
Haruhiko Dekura<br>
<br>
<br>
<br>
<br>
<br>
<br>
========================================<br>
<br>
<br>
Haruhiko Dekura<br>
<br>
<br>
Postdoctoral Fellow<br>
<br>
<br>
Senior Research Fellow Center, Ehime University, 2?5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan<br>
=====================================<br>
<br>
<br>
<br>
<br>
<br>
Dear all,<br>
<br>
I am trying to get the band structure and the DOS of a Grain boundary system of 60 atoms.<br>
<br>
(1) The band structure seems ok but when I am trying to set the Fermi energy to be the reference (i.e at 0) where two bands cross, it is not working i.e. I am still getting that the two bands still cross at a negative value (my Fermi energy is -0.098eV). Why is this happening?<br>
<br>
(2) The DOS of the system is not zero at zero energy (maybe this is a consequence of 1) and it is a bit wiggly as well (see graph attached)<br>
<br>
<br>
Thanks in advance<br>
<br>
Regards<br>
<br>
Elie Moujaes<br>
University of Nottingham<br>
NG7 2RD<br>
UK<br>
<br>
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