[Pw_forum] Query regarding Al2O3 system slab calculation
Vikas Varshney wrote: > Dear All, > > My final motivation is to simulate adsorption of several small > molecules on Al2O3 slab. The strategy I am undertaking (and hence I > have few questions) is below. Please correct me if I am wrong at any > stage of my calculation. > > I want to get the ground state of the Al2O3 slab. In this regard, I > got the unit cell of Al2O3 which is trigonal ( Space group R-3c, point > group D3d, 30 atoms) . This is not the primitive unit cell (which is > rhombhohedral and contain 10 atoms). The reason is to eventually > simulate 0 0 1 surface. It seems that the structure consist of 2 basis > atoms. The rest are defined by different symmetry operations for the > point group of Al2O3. > > Is is possible to make use of symmetry operations and run the > calculation on unit cell of Al2O3 by specifying only two basis atoms > and then run slab calculation with 30 atoms? Or should I just create > a 30 atom unit cell with vacuum along Z direction in a slab geometry > and relax it? I am not clear about your question much. Anyway, I do the simulation of adsorption on the slab by form a supercell that stores the substrate + vacuum + adsorbate atoms. You can see in previous archives to understand how to form a supercell. Best, Linh > Best Regards, > Vikas > > > > > ___ > 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] Query regarding Al2O3 system slab calculation
Dear Lin, Thank you very much for your answer. I will definitely go through the archives now you have mentioned supercell approach. Best Regards, Vikas On Wed, Jun 2, 2010 at 5:07 AM, Ngoc Linh Nguyen wrote: > Vikas Varshney wrote: > > Dear All, > > > > My final motivation is to simulate adsorption of several small > > molecules on Al2O3 slab. The strategy I am undertaking (and hence I > > have few questions) is below. Please correct me if I am wrong at any > > stage of my calculation. > > > > I want to get the ground state of the Al2O3 slab. In this regard, I > > got the unit cell of Al2O3 which is trigonal ( Space group R-3c, point > > group D3d, 30 atoms) . This is not the primitive unit cell (which is > > rhombhohedral and contain 10 atoms). The reason is to eventually > > simulate 0 0 1 surface. It seems that the structure consist of 2 basis > > atoms. The rest are defined by different symmetry operations for the > > point group of Al2O3. > > > > Is is possible to make use of symmetry operations and run the > > calculation on unit cell of Al2O3 by specifying only two basis atoms > > and then run slab calculation with 30 atoms? Or should I just create > > a 30 atom unit cell with vacuum along Z direction in a slab geometry > > and relax it? > I am not clear about your question much. > Anyway, I do the simulation of adsorption on the slab by form a > supercell that stores the substrate + vacuum + adsorbate atoms. > You can see in previous archives to understand how to form a supercell. > > Best, > > Linh > > > > > > > > > > Best Regards, > > Vikas > > > > > > > > > > ___ > > 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 > -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100602/d6354d6c/attachment.htm
[Pw_forum] Query regarding Al2O3 system slab calculation
Dear All, My final motivation is to simulate adsorption of several small molecules on Al2O3 slab. The strategy I am undertaking (and hence I have few questions) is below. Please correct me if I am wrong at any stage of my calculation. I want to get the ground state of the Al2O3 slab. In this regard, I got the unit cell of Al2O3 which is trigonal ( Space group R-3c, point group D3d, 30 atoms) . This is not the primitive unit cell (which is rhombhohedral and contain 10 atoms). The reason is to eventually simulate 0 0 1 surface. It seems that the structure consist of 2 basis atoms. The rest are defined by different symmetry operations for the point group of Al2O3. Is is possible to make use of symmetry operations and run the calculation on unit cell of Al2O3 by specifying only two basis atoms and then run slab calculation with 30 atoms? Or should I just create a 30 atom unit cell with vacuum along Z direction in a slab geometry and relax it? Best Regards, Vikas -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100601/cb2e45e5/attachment.htm
