[Pw_forum] DOS of graphene

[Giovanni Cantele]

> Dear all,
> I have plotted the density of states of graphene but when I looked at the
> graph, DOS was not zero at the fermi level (I got it to be -0.988 eV). my
> Programm seems pretty fine and i have checked it several times but with in
> vain..You will find attached the ps version and the input for the dos.x
> command...
> Regards
> Elie Moujaes
> University of Nottingham
> NG7 2RD
> UK

The problem that the Fermi level is not at the energy you expect might not
be related to a mistake. The zero energy is not well defined in a
plane-wave calculation (try to browse the forum, there should be more than
one topic about that!). One should compute the DOS, then calculate the
Fermi energy (as the energy at which the integrated DOS matches the number
of the electrons), then for the sake of clarity you can shift you DOS (or
band structure) plot so as the Fermi energy is at 0.

However, this might not be the problem in you calculation.
I'm not very sure that your calculation is right, because the shape of
your DOS plot does not look like the one of graphene. So the first problem
to solve is to understand on the top of which scf / nscf calculation you
have built your DOS plot. Unless I missed something, there are not
sufficient elements to understand what happened.

Giovanni

-- 
Giovanni Cantele, PhD
CNR-SPIN and Dipartimento di Scienze Fisiche
Universita' di Napoli "Federico II"
Complesso Universitario M. S. Angelo - Ed. 6
Via Cintia, I-80126, Napoli, Italy
Phone: +39 081 676910 - Fax:   +39 081 676346
Skype contact: giocan74

ResearcherID: http://www.researcherid.com/rid/A-1951-2009
Web page: http://people.na.infn.it/~cantele
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