Dear Loc Duong Dinh? The band structure must be different between 2 and 8 atoms in every unit cell. The coordinate of M point of 2 atoms is different from that of 8 atoms, for the length of primitive vectors are different. Furtheremore, there are 8 valence electrons in 2 atoms' unit cell. However, there are 32 velence electrons in 8 atoms' unit cell. I think you can refer to textbook of solid state physics for more imformation. On Thu, Jul 22, 2010 at 11:16 AM, loc duong ding <mambom1902 at yahoo.com>wrote:
> Dear all, > > I have a problem when I calculate band structure of graphene. The band > structure > of graphene calculated by unit of 2 atoms and 8 atoms is different. the gap > at > gama point as well as M point are totally different. > > > In general case, unit of 2 atoms and unit of 8 atoms both create graphene > strucutre. I can not unserstand why they are different? Is my understanding > is > wrong? > > > I know this is the general question but I hope I can receive helpful > instructions. > > > I aprreciate all ypur helps. > > Sincerely,----------------------------------------------- > Loc Duong Dinh > Ms-Ph.D Student > Sungkyunkwan Advanced Institute of Nanotechnology, > Sungkyunkwan University, > Suwon, 440-746, Korea > Email: mambom1902 at yahoo.com, ddloc at skku.edu > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- ____________________________________ Hui Wang School of physics, Nankai University, Tianjin, China -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100722/89568736/attachment.htm
