One can't choose between supercell and ibrav=0. Ibrav defines the bravais index. Hence it defines the crystalline geometry, symmetry group. Supercell is a method for studying the periodic boundary condition in solid-state physics.
What ever the ibrav is, one need to define a supercell (direct or indirect way). For study the surface reconstruction, one may use ibrav=0 in order to avoid pre-chosen bravais index. It's just a guess. I haven't done so. -------------------------------------------------- Duy Le PhD Student Department of Physics University of Central Florida. "Men don't need hand to do things" On Thu, Mar 11, 2010 at 4:07 AM, Ngoc Linh Nguyen <nnlinh at sissa.it> wrote: > It's also ok with the ?cell-parameters of only either cubic or hexagonal. > > So I prefer using supercell then putting ibrav=0 > > Linh > > > Duy Le wrote: >> How about ibrav=0? >> -------------------------------------------------- >> Duy Le >> PhD Student >> Department of Physics >> University of Central Florida. >> >> "Men don't need hand to do things" >> >> >> >> On Wed, Mar 10, 2010 at 4:59 AM, Ngoc Linh Nguyen <nnlinh at sissa.it> wrote: >> >>> mohnish pandey wrote: >>> >>>> ? ? ? ? ? ? ? ? ? ?I want to get the results for surface >>>> reconstructions computationally, but the problem is as we have specify >>>> the "ibrav" i.e symmetry of the system the relax calculation only >>>> optimizes the structure within the given symmetry. >>>> >>> Not exactly, the relax calculation plays a role to find out an optimal >>> configuration from an initial configuration. >>> If you want to consider the surface reconstruction of given material, >>> you should build a supercell in that the defect or adatom can be existed. >>> >>> And how to form a supercell. Let see the previous archives of PW_forum >>> >>> Good luck >>> >>> Linh >>> >>> >>> >>> >>> -- >>> ----------------------------------------------------- >>> ?Nguyen Ngoc Linh, PhD Student >>> ?c/o: ? SISSA & CNR-INFM Democritos, >>> ? ? ? ?via Beirut 2-4, 34014 Trieste (Italy) >>> ?email: nnlinh at sissa.it >>> ?phone: +39 04 03787 319 >>> ?skype: ngoclinh84phys >>> ----------------------------------------------------- >>> "The physics is theoretical but the fun is real" >>> >>> >>> _______________________________________________ >>> 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 >> > > > -- > ----------------------------------------------------- > ?Nguyen Ngoc Linh, PhD Student > ?c/o: ? SISSA & CNR-INFM Democritos, > ? ? ? ?via Beirut 2-4, 34014 Trieste (Italy) > ?email: nnlinh at sissa.it > ?phone: +39 04 03787 319 > ?skype: ngoclinh84phys > ----------------------------------------------------- > "The physics is theoretical but the fun is real" > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
