On Thu, Mar 10, 2011 at 9:52 AM, Eric Germaneau <germaneau at gucas.ac.cn> wrote: > Dear Mehmet and Hui Wang, > > That's what I did. > From my calculations the occupied and unoccupied bands touch only at K > point. > I was just confused because the scf calculation does not output a zero gap. > I mean the line "highest occupied, lowest unoccupied level" shows two > different values and I expected them to be equal. This was just explained by Mehmet. Check it again > So, it seems I did not too bad in fact. > But how to experimentally get a zero gap then? > Thanks, > > ??????????????????? Eric. >
-------------------------------------------------- Duy Le PhD Student Department of Physics University of Central Florida. "Men don't need hand to do things" > On 03/09/2011 07:02 AM, Mehmet Topsakal wrote: > > 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 >>> >>> 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 > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- > Be the change you wish to see in the world > ? Mahatma Gandhi ? > > Dr. ?ric Germaneau > > 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 > >
