[Pw_forum] (no subject)

[Giovanni Cantele]

> On 01 Dec 2015, at 09:02, Tariq Sami <tariq.sami72 at yahoo.com> wrote:
> 
> Dear all,
>      I have a (very basic) question regarding band structure calculations. 
> One requires Fermi energy for band structure calculations but the are two different Fermi energies in the
> scf and nscf outputs. Can anyone please tell which one should i use and what's the basic difference?
> Thanks in advance
> 
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How much do they differ?

Consider that the calculation of the Fermi level requires an integration over a fine grid in the BZ. Usually, what one can do is to make a DOS calculation, with a much finer k-point grid than in the scf run, and then to use the definition of the Fermi level to compute it, that is, the DOS integral from the lowest energy to the Fermi level is equal to the total number of electrons in your system. However, the value from the scf run should be accurate!

Giovanni



-- 

Giovanni Cantele, PhD
CNR-SPIN
c/o Dipartimento di Fisica
Universita' di Napoli "Federico II"
Complesso Universitario M. S. Angelo - Ed. 6
Via Cintia, I-80126, Napoli, Italy
e-mail: giovanni.cantele at spin.cnr.it
Phone: +39 081 676910
Skype contact: giocan74

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