Dear Dr. Apsi, Thank you for the explanation.
I considered the Fermi energy value from Non-self consistent calculation (NSCF). As you say broadening is responsible for these few states on the fermi energy, will it be helpful if I change the smearing type??? (Pardon me if the question is pointless, I am not yet very good with the core physics stuff) I have used m-v smearing for the calculations, what if I use the tetrahedra or other smearing method... will it be helpful to avoid this issue ?? Requesting your insight, please. Sincerely, B S Bhushan, Ph.D Scholar, ABV- Indian Institute of Information Technology and Management, Gwalior. www.bsbhushan.com On Tue, May 22, 2018 at 2:42 PM, Ari P Seitsonen <[email protected]> wrote: > > Dear B S Bhushan, > > To me it looks like > > 1) QE/PWscf sets the Fermi level in the band gap, at some arbitrary > energy just so that the number of electrons is conserved: It could be > higher (but hardly lower). This is normal, as the energy position is not > specifically defined so long as the number of electrons is correct (or, the > Fermi level can be anywhere in the band gap just as it is far enough from > the valence and conduction band edges) > > 2) the program to calculate DOS does not realign the Fermi energy, so > with the broadening there appears some intensity at the Fermi energy > > After you check that this is the correct assumption (for example that > the occupation of all bands is either 0 or 1), you can manually shift the > Fermi energy to mid-gap in the plots; or, some people do not show the Fermi > energy at all in systems with gap but align the energy scale so that the > top of the valence band ("valence band maximum", "VBM") is at zero. > > Which value of Fermi energy do you use actually, the one from the > self-consistent or non-self-consistent calculation? > > Greetings from Sunny Paris, > > apsi > > -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*= > -=*=-=*=-=*=-=*=- > Ari Paavo Seitsonen / [email protected] / http://www.iki.fi/~apsi/ > Ecole Normale Supérieure (ENS), Département de Chimie, Paris > Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935 > > > > On Mon, 21 May 2018, B S Bhushan wrote: > > Dear Experts, >> I am analyzing doped graphene using pbe functional. >> Where, I end up having contradictory DOS and Band structure. >> >> The Band structure shows a small band gap at the fermi level, however, >> the DOS shows few states on the fermi level. >> >> What should I call the system in such cases, metallic or semi-metall >> ic or semi-conducting ??? >> >> or have I done something wrong ??? >> >> The link below contains the figures and input scripts used by me. >> https://drive.google.com/open?id=11Q7xfMGCHJDUlPK0amTnWO-y4R70ZQWj >> >> Please suggest. >> >> >> Sincerely, >> B S Bhushan, >> Ph.D Scholar, >> ABV- Indian Institute of Information Technology and Management, Gwalior. >> www.bsbhushan.com >> >> >> > _______________________________________________ > users mailing list > [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users >
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