[Wien] Regarding use of WIEN 2K for two dimensional problems

[Laurence Marks]

I suggest that you look in the literature for what people have used for
graphene to get the band-gap "right". It may be only some functionals, or
there may be issues with the 2D lattice parameters -- no idea. I am sure
this has been done (many times), probably with numerous degrees of
approximation all the way up to double-hybrids or GW.

Bi-layer graphene is a similar calculation, except you have to worry about
the spacing and the fact that simple functionals such as PBE are not very
good for the VDW component of the bonding. Maybe WC -- again check the
literature.

What do you mean by "intercalated graphene" -- intercalated graphite? That
is more complicated as you how to decide what concentration of intercalants
to use, where, and more. Maybe also some papers on this.

If you are really lucky someone will send relevant references....

On Fri, Jan 25, 2013 at 9:08 AM, Krisna Swaroop Sharma <
sharma.krishnaswaroop at gmail.com> wrote:

>  Dear Prof. Marks
> Thanks a lot for extending a valuable suggestion. It works. I tested it
> for 10 Aungstrom. However in the band structure of graphene the v. band and
> c band touch at K point about 10 eV below EF and at EF band gap of about
> 0.5 eV is obtained. I suppose by changing the value of 'c' , a suitable
> value of  'c' may be obtained to give realistic electron energy bands for
> single layer graphene? Should I go ahead as proposed above or take some
> other measure?
> Another problem is how to proceed for the case of bi-layer graphene and
> intercalated graphene?
> Your suggestions will prove to be of great value to us. Awaiting your
> reply & with kind regards.
> Sincerely Yours
> Dr. K.S. Sharma
> The IIS University, Jaipur (India)
> <sharma.krishnaswaroop at gmail.com>
> .
>
> On Tue, Jan 22, 2013 at 8:11 PM, Laurence Marks <L-marks at northwestern.edu>wrote:
>
>> You have to make c large enough to represent an isolated layer. Wien2k
>> and most (not all) DFT codes are periodic in 3D. Perhaps c=8 Angstroms is
>> OK..
>>
>>
>> On Tue, Jan 22, 2013 at 8:35 AM, Krisna Swaroop Sharma <
>> sharma.krishnaswaroop at gmail.com> wrote:
>>
>>> Dear Peter Blaha and WIEN users
>>> I was trying to solve the problem of electronic structure of 'Graphene'
>>> using WIEN 2K. For this purpose I provide a=b=1.42A, c=0, angles alpha=90,
>>> beta=90, gamma=120 and space group 191 (P6mmm), so as to obtain StructGen
>>> for graphine, but the software does not accept c=0 and it automatically
>>> makes c=1.42A, which is not true for graphene. Though it works well for
>>> graphite when value of c is given. Can any body help me how to use WIEN 2K
>>> for 2-dimensional and 1-dimensional problems.
>>> Expecting an early help & with kind regards in anticipation.
>>> K.S. Sharma
>>> The IIS University, Jaipur, India
>>> <sharma.krishnaswaroop at gmail.com>
>>>
>>>
>>
>>
>>   --
>> Professor Laurence Marks
>> Department of Materials Science and Engineering
>> Northwestern University
>> www.numis.northwestern.edu 1-847-491-3996
>> "Research is to see what everybody else has seen, and to think what
>> nobody else has thought"
>> Albert Szent-Gyorgi
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
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>>
>>
>


-- 
Professor Laurence Marks
Department of Materials Science and Engineering
Northwestern University
www.numis.northwestern.edu 1-847-491-3996
"Research is to see what everybody else has seen, and to think what nobody
else has thought"
Albert Szent-Gyorgi
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