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 <nkxirainbow at gmail.com> wrote: > 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 <germaneau at > gucas.ac.cn>wrote: > >> 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. >> >> -- >> * Be the change you wish to see in the world >> * ? Mahatma Gandhi ? >> >> Dr. ?ric Germaneau <germaneau at gucas.ac.cn> >> >> College of Physical Sciences >> Graduate University of Chinese Academy of Sciences >> Yuquan Road 19A >> Beijing 100049 >> China >> >> * Please consider the environment before printing this email. >> Consid?rez svp l'environnement avant d'imprimer cet email. * >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> > > > -- > ____________________________________ > Hui Wang > School of physics, Fudan University, Shanghai, China > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- 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 http://www.researcherid.com/rid/A-5015-2010 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110309/ceea9138/attachment.htm
