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Did you read what I said?<br>
Got it.<br>
By the way, I've just realized that I did not thank Mehmet and Hui
Wang.<br>
<br>
<br>
On 03/09/2011 08:57 PM, Duy Le wrote:
<blockquote
cite="mid:AANLkTimL1crBSMbHHrRTa3at4tc-VCdpyFyjOZYBwTYx@mail.gmail.com"
type="cite">
<pre wrap="">On Thu, Mar 10, 2011 at 9:52 AM, Eric Germaneau <a class="moz-txt-link-rfc2396E" href="mailto:germaneau@gucas.ac.cn"><germaneau@gucas.ac.cn></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Dear Mehmet and Hui Wang,
That's what I did.
>From my calculations the occupied and unoccupied bands touch only at K
point.
I was just confused because the scf calculation does not output a zero gap.
I mean the line "highest occupied, lowest unoccupied level" shows two
different values and I expected them to be equal.
</pre>
</blockquote>
<pre wrap="">This was just explained by Mehmet. Check it again
</pre>
<blockquote type="cite">
<pre wrap="">So, it seems I did not too bad in fact.
But how to experimentally get a zero gap then?
Thanks,
Eric.
</pre>
</blockquote>
<pre wrap="">
--------------------------------------------------
Duy Le
PhD Student
Department of Physics
University of Central Florida.
"Men don't need hand to do things"
</pre>
<blockquote type="cite">
<pre wrap="">On 03/09/2011 07:02 AM, Mehmet Topsakal wrote:
Dear Eric,
In addition, if you select 18x18x1 kpoints, your mesh should include both K
and M points.
But for a band-structure calculation, you should arrange a kpoints list
along special directions, such as from GAMMA-to-M-to-K-to-GAMMA, and do a
nscf calculation....
On Wed, Mar 9, 2011 at 11:28 AM, xirainbow <a class="moz-txt-link-rfc2396E" href="mailto:nkxirainbow@gmail.com"><nkxirainbow@gmail.com></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">
Dear Eric:
The occupied and unoccupied bands touch each other only at M point(or K
point, I forget it).
You must include this point in you k-mesh.
Furthermore, if you include spin-orbital coupling, the band gap will be
opened at this point.
On Thu, Mar 10, 2011 at 1:30 AM, Eric Germaneau <a class="moz-txt-link-rfc2396E" href="mailto:germaneau@gucas.ac.cn"><germaneau@gucas.ac.cn></a>
wrote:
</pre>
<blockquote type="cite">
<pre wrap="">
Dear all,
I'm trying to compute graphene's band gap but get stuck.
>From my understanding a scf calculation should provide the same energy
for the highest occupied and lowest occupied level which means a zero gap.
I played with the number a kpoints a finally got a band gap of 0.57 which
is not null.
The scf convergence looks good.
I'm not (yet) an expert in DFT calculation so may did something wrong or
misunderstood something here.
So, I wonder if someone has already successfully performed such
calculation.
I have attached my input file.
Thanks in advance,
Eric.
--
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Dr. Éric Germaneau
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Graduate University of Chinese Academy of Sciences
Yuquan Road 19A
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<pre wrap="">
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School of physics, Fudan University, Shanghai, China
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<pre wrap="">
--
Mehmet Topsakal (Ph.D. Student)
UNAM-Institute of Materials Science and Nanotechnology.
Bilkent University. 06800 Bilkent, Ankara/Turkey
Tel: 0090 312 290 3527 ; Fax: 0090 312 266 4365
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Be the change you wish to see in the world
— Mahatma Gandhi —
Dr. Éric Germaneau
College of Physical Sciences
Graduate University of Chinese Academy of Sciences
Yuquan Road 19A
Beijing 100049
China
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<br>
<a href="mailto:germaneau@gucas.ac.cn">Dr. Éric Germaneau</a><br>
<br>
College of Physical Sciences<br>
Graduate University of Chinese Academy of Sciences<br>
Yuquan Road 19A<br>
Beijing 100049<br>
China<br>
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