[QE-users] k-points selection for Band Structure calculation

[pboulet]

Hello,

You can find the k vectors for hexagonal Si here:
https://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-kv-list <https://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-kv-list>
I have chosen the "simplest" hexagonal system (n°168), but you can change it if necessary here:
https://www.cryst.ehu.es/cryst/get_kvec.html <https://www.cryst.ehu.es/cryst/get_kvec.html>

From the list of k vectors you can choose the path you want to follow for your calculations. The path can be generated with xcrysden:
http://www.xcrysden.org/ <http://www.xcrysden.org/>

Now, for the lists of k vectors you are mentioning below, both are valid: the choice for the path is at your discretion. But, if you want to check your results by comparing with other works, then you may want to choose the same path.

HTH,
Pascal


Pascal Boulet
—
Professor in computational materials - DEPARTMENT OF CHEMISTRY
University of Aix-Marseille - Avenue Escadrille Normandie Niemen - F-13013 Marseille - FRANCE
Tél: +33(0)4 13 55 18 10 - Fax : +33(0)4 13 55 18 50
Email : pascal.boulet at univ-amu.fr <mailto:pascal.boulet at univ-amu.fr>



> Le 20 mai 2020 à 20:10, Chaman Gupta <chaman at uw.edu> a écrit :
> 
> Hey everyone,
> 
> I am trying to study the effect of pressure on the band structure of 'Si - simple hexagonal (Phase V)', which is stable between 17 to 30 GPa (approx.)
> 
> Here is a paper published in Nature (https://www.nature.com/articles/s41586-020-2150-y <https://www.nature.com/articles/s41586-020-2150-y>), which has a figure with the band structure of Hex-Si (image is attached). The image has " A, Gamma, M, U, L " k-points.
> 
> IMAGE 1 IS HERE <https://drive.google.com/file/d/1zaJSjv3RX3gy87NTuBV5AjkJysW7pdOZ/view?usp=sharing>
> 
> When I looked for BZ1 or high symmetry points for simple hexagonal structure, I came across this link (http://lamp.tu-graz.ac.at/~hadley/ss1/bzones/hexagonal.php <http://lamp.tu-graz.ac.at/~hadley/ss1/bzones/hexagonal.php>) (Image attached). It mentions the Symmetry points to be "Gamma, A, K, H, M, L"
> 
> IMAGE 2 IS HERE <https://drive.google.com/file/d/1D4-buR2XPTlP5LzIypFjcehicfPg3YZO/view?usp=sharing>
> 
> My questions:
> 
> 1. From what I understand, symmetry points are dependent on the type of lattice, and highly affect the band structure. Is this statement right or wrong?
> 
> 2. Which k-points/ High symmetry points/ BZ1 should I use for my band structure calculation?
> 
> 3. Is it possible, by any chance the author of this Nature paper, might have used the wrong k-points? Or should I use what they have used?
> 
> Thanks for the help
> 
> Regards,
> 
> Chaman Gupta
> Graduate Research Student, Novosselov Research Group <http://depts.washington.edu/nrglab/>, UW
> Graduate Research Student, Pauzauskie Research Group <https://depts.washington.edu/pzlab/wordpress/>, UW
> University of Washington Seattle, M.S. in Mechanical Engineering
> IIT Kharagpur, B.Tech in Metallurgical and Materials Engineering
> Linked In <https://www.linkedin.com/in/professorchamangupta> | Email <mailto:chaman at uw.edu> | P: +1 (206) 383-3514
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