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Dear Elje,<br>
<br>
since you are dealing with a slab geometry and you want to apply the
field along the direction perpendicular to the surface, why don't you
use the sawtooth potential (tefield=.TRUE. instead of lefield=.TRUE.)
to generate the E field?<br>
<br>
On 09/28/2010 10:41 PM, Elie Moujaes wrote:
<blockquote cite="mid:SNT114-W1041A2D46423E5E7C62FF9D3660@phx.gbl"
type="cite">
<style><!--
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
font-size: 10pt;
font-family:Tahoma
}
--></style>Dear
all,<br>
I<br>
I am trying to get the band structure of graphene under the effect of
an electric field. The problem is that the result at the end is very
messy and jiggly. I repeated the calculations many times but I still
get the same result. I first performed a scf calculation without the
electric field followed by a scf calculation with an electric field and
then the band calculation.<br>
<span style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span></font><o:p></o:p></span>
<br>
</blockquote>
<br>
Do you have some evidence that your "messy and jiggly" band structure
is wrong? Are you sure that you are visualizing it in the correct way?<br>
<br>
<br>
HTH<br>
<br>
<br>
GS<br>
<br>
<blockquote cite="mid:SNT114-W1041A2D46423E5E7C62FF9D3660@phx.gbl"
type="cite"> <br>
SCF with electric field<br>
<br>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3">&control<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>prefix='bi elgraphene',<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>calculation='scf',<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>restart_mode='from_scratch',<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>lelfield = .true.,<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><font size="3"><span
style="font-family: 'Courier New';" lang="EN-GB"><span style=""> </span></span><span
style="font-family: 'Courier New';" lang="PT-BR">pseudo_dir =
'/espresso-4.2/pseudo/',<o:p></o:p></span></font></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><font size="3"><span
style="font-family: 'Courier New';" lang="PT-BR"><span style=""> </span></span><span
style="font-family: 'Courier New';" lang="EN-GB">outdir='/tmp/results_MOUJAES/'<o:p></o:p></span></font></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>/<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>&system<span style=""> </span><o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>ibrav=<span style=""> </span>4, celldm(1)
=4.608737, celldm(3)=5.330410, nat=4, ntyp= 1,<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>ecutwfc =
110.D0,occupations='smearing',smearing='methfessel-paxton', degauss=0.01<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3">/<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>&electrons<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>conv_thr=1.D-10,<span style=""> </span><o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>mixing_mode='plain'<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>efield_cart(1) = 0.0,<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>efield_cart(2) = 0.0,<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>efield_cart(3) = 0.001,<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>startingwfc = 'random'<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><o:p><font size="3"> </font></o:p></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>/<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3">ATOMIC_SPECIES<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>C<span style=""> </span>12.0107<span style=""> </span>C.pz-vbc.UPF<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3">ATOMIC_POSITIONS
crystal<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>C 0.000000<span style=""> </span>0.000000<span
style=""> </span>0.000000<span style=""> </span><o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>C 0.000000<span style=""> </span>0.000000<span
style=""> </span>0.257692 <o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>C 0.333333<span style=""> </span>-0.33333<span
style=""> </span>0.000000<span style=""> </span><o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>C -0.333333<span style=""> </span>0.33333<span
style=""> </span>0.257692<span style=""> </span><o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><o:p><font size="3"> </font></o:p></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3">K_POINTS
automatic<o:p></o:p></font></span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3"><span
style=""> </span>38 38 1<span style=""> </span>0 0 0<span style="">
</span></font><o:p></o:p></span></p>
<br>
I noticed that part of the bands calculation output had a problem with
the convergence of one of thh eigenavalues as some of the input looked
like:<br>
<br>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"><font size="3">per-process
dynamical memory:<span style=""> </span>30.2 Mb<br>
<br>
<span style=""> </span>Band Structure Calculation<br>
<span style=""> </span>Davidson diagonalization with overlap<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged<br>
<span style=""> </span>c_bands:<span style=""> </span>1
eigenvalues not converged</font><br>
</span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"></span> </p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB">Please can anyone
suggest me of what could have gone wrong...</span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"></span> </p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB">Thanks</span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB"></span> </p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB">Elie Moujaes</span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB">University of
Nottingham</span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB">NG7 2RD</span></p>
<p class="MsoPlainText" style="margin: 0in 0in 0pt;"><span
style="font-family: 'Courier New';" lang="EN-GB">UK</span></p>
<pre wrap="">
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</blockquote>
<br>
<br>
<pre class="moz-signature" cols="72">--
Gabriele Sclauzero, EPFL SB ITP CSEA
PH H2 462, Station 3, CH-1015 Lausanne
</pre>
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