Dear Loc Duong Dinh, have you haver heard about "refolding" of the band structure (in the context of supercells)? If not, first have a look at some good electronic structure textbook. The band structure is actually the same, but in practice you are visualizing it in a different way. Try to compute the (fully converged) DOS for the two different unit cells and compare them (with appropriate weights). What do you see?
GS Il giorno 22/lug/2010, alle ore 05.16, loc duong ding ha scritto: > 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 ? Gabriele Sclauzero, EPFL SB ITP CSEA PH H2 462, Station 3, CH-1015 Lausanne -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100722/ed7a2f2b/attachment.htm -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 1753 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20100722/ed7a2f2b/attachment.bin
