QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: luigi9213 on January 22, 2015, 16:23
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Hi, I've some problem with the band structure of Bismuth Selenide (Bi2Se3). There is some explanation in this article http://iopscience.iop.org/0953-8984/9/2/014/pdf/c70213.pdf (http://iopscience.iop.org/0953-8984/9/2/014/pdf/c70213.pdf). I've used this .CIF file in the VNL builder https://github.com/cryos/avogadro/blob/master/crystals/selenides/Bi2Se3.cif (https://github.com/cryos/avogadro/blob/master/crystals/selenides/Bi2Se3.cif). But when i tried to simulate i hadn't the same Brillouin zones of the article.
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Using the rhombohedral cell is quite difficult. I can try to give you some tips later on, if really needed. However, if you look into the more modern literature about topological insulators, you will find that most use the hexagonal supercell for calculations, and then it's a lot easier because ATK has all the relevant symmetry points and the notation is standardized.
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Please help me, i really need help!!! I must do the bandstructure of bismuth telluride like this paper (http://iopscience.iop.org/0953-8984/9/2/014/pdf/0953-8984_9_2_014.pdf)
With hexagonal lattice there isn't the same brillouin zone... Helppp
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Ok, you need to use the customized solution presented here: http://quantumwise.com/forum/index.php?topic=2096.msg9939#msg9939 (don't read the posts below this post, they were only relevant in older ATK versions).
Now, you also need to know the coordinates of the symmetry points. Most literature will always use the hexagonal setting for the trigonal space groups, but an old book I have by Lax gives the following coordinates for the F and L points:
F: 1/2, 0, 0
L: 1/6, 1/3, 1/6
If this agrees with the paper you mention should be verified, to be on the safe side! We are actually working on a tool to help visualizing the Brillouin zone and the symmetry points, so we can use that later to check.