Dear Ali You can start with (lateral) surface reconstruction of your bulk system. Afterwards I would try different supercells with different starting points, like number of atoms or "surface molecules". Don't forget to saturate dangling bonds (even there you can check different types). I think in Si NWs even a SiH3 group is outermost for some NWs After relaxing your structures you can check the most favorable ones by comparing energies (have a look at surface calculations for details). Good luck
Marcel Mohr -- Institut f?r Festk?rperphysik TU Berlin On Tue, 21 Apr 2009, Prasenjit Ghosh wrote: > Dear Ali, > > It depends on the type of reconstruction the surface of the nanowire > undergoes.? May be if you tell a bit more about the type of reconstruction, I > can tell you more. > > Prasenjit. > > 2009/4/21 ali kazempoor <kazempoor2000 at yahoo.com> > Dear Prasenjit > Thank you for your reply, but I mean what I do to see the surface > reconstruction at lateral nanowire surface. For simulation of a nanowire > in z direction we add vaccum around nanowire in x and y and for z we use > periodic boundary condition . So if we only suppose one unit > repetation in z , we can not observe the surface reconstruction . Therefor > for observing reconstruction , I think we have to make for > example twice unit repetation in z or more. > thanks > > --- On Tue, 4/21/09, Prasenjit Ghosh <prasenjit.jnc at gmail.com> wrote: > > From: Prasenjit Ghosh <prasenjit.jnc at gmail.com> > Subject: Re: [Pw_forum] reconstruction > To: "PWSCF Forum" <pw_forum at pwscf.org> > Date: Tuesday, April 21, 2009, 10:38 AM > > > Dear Ali, > > Usually when you speak of simulating a nanowire, because of the periodic > boundary conditions, you simulate an infinite one. If the > nanowire is aligned along Z axis, which seems to be your case,? then you have > periodicity along the Z-direction. Therefore you need > to? have enough vacuum along the x & y direction so that the periodic images > should not interact. > > Prasenjit. > > 2009/4/20 ali kazempoor <kazempoor2000 at yahoo.com> > > Dear all > I want to study the fingerprint of reconstruction in nanowire facets. > How can ?I find that wheater I have surface > reconstruction or not? Should I make a bigger supercell in Z direction( > Z is the lenght of nanowire)? > thanks > Ali Kazempour.Isfahan University of Technology,Iran > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > -- > PRASENJIT GHOSH, > POST-DOC, > ROOM NO: 265, MAIN BUILDING, > CM SECTION, ICTP, > STRADA COSTERIA 11, > TRIESTE, 34104, > ITALY > PHONE: +39 040 2240 369 (O) > ? ? ? ? ? ? ?+39 3807528672 (M) > > -----Inline Attachment Follows----- > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > -- > PRASENJIT GHOSH, > POST-DOC, > ROOM NO: 265, MAIN BUILDING, > CM SECTION, ICTP, > STRADA COSTERIA 11, > TRIESTE, 34104, > ITALY > PHONE: +39 040 2240 369 (O) > ? ? ? ? ? ? ?+39 3807528672 (M) > >
