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 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110309/2ecade03/attachment.htm
