[Pw_forum] high symmetric Points

[dingfu.shao]

Hi, BENYAHIA NEZHA, 

if the k_vector is :
k_vec=[kx1 ky1 kz1]
           [kx2 ky2 kz2]
           [kx3 ky3 kz3];

If you have a kpoint with the crystal coordinates, like (x',y',z'). It's easy to translate it into the tpiba style using the following relations:

x_tpiba = x' * kx1 + y' * kx2 + z' * kx3
y_tpiba = x' * ky1 + y' * ky2 + z' * ky3
z_tpiba = x' * kz1 + y' * kz2 + z' * kz3

So you can write a small code to read the kpoint data generated from xcrysden, and translate them in to tpiba style. You can compare the result with the kpoint from plotphon.

BTW, the plotphon is easy and convenient, why don't you want to use it?


Dingfu Shao
 
 





Dingfu Shao, Ph.D 
Institute of Solid State Physics
Chinese Academy of Sciences
P. O. Box 1129
Hefei 230031
Anhui Province
P. R. China
Email: dingfu.shao at gmail.com

From: BENYAHIA NEZHA
Date: 2014-05-03 18:50
To: pw_forum at pwscf.org
Subject: [Pw_forum] high symmetric Points
Dear Ari Paavo Seitsonen

First, thank you for your response. You're so helpfull.
If i understood, Xcrysden generates a crystal coordinates(Reciprocal coordinates) but it gave me a wrong dispersion curve when plotted. By your response you mean that the coordinates which were pasted below (and were generated by plothon) are in the tpiba(2pi/a) unit, without forgetting that these ones gave me the right dispersion curve. Can xcrysden give me a tpiba coordinates inspite of reciprocal ones? and how?
In this case how to generate tpiba coordinates(which give me the right dispersion curve) without using Plotphon????? 

I will be very happy if you could enlightened me more on this "as the second point looks like (-1/3,2/3) above but contains apparently the 1/sqrt(3) ~= 0.57735... in the generated k points. What is 1/sqrt(3) ~= 0.57735????  
I'am sorry if i have asked a lot of questions but i really need all of them!!!!!!


Regards.
Nh Ben
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