Hello Smita Patir.

Usually we do a few runs changing parameters, like energy cutoff or the number of k-points. Convergence is related to energy minimum, you will see that as much you increase k-points, you will reach a minimum energy, but then if you increase more, the energy can rise again. So there is a point of minimum energy related to number of k points. You can do it with energy cutoff. Feel free to reply if you need more help with this.

Best regards,

Ricardo Tadeu

Ricardo Tadeu Maia Thank you for the answer.

Besides xcrysden, what other tools or methods can we use to set the k-points along the high symmetry path ? what do {crystal_b} and {tpiba_b} mean in k_points setting ? k_points (Automatic) 5 5 5 0 0 0 and 6 5 4 1 1 1, what's the difference?

Hello Smita Patir

There is a site, Seekpath, where you upload your unit cell CIF and it generates the high symmetry points. I don't know what is the difference of crystal_b and tpiba_b, sorry. The values of k points (automatic) is when QE will choose automatically the k-points according to the number you provide. 5 5 5 means it will choose 5 points in x directions, 5 points in y direction, and 5 points in z direction. Which means that as you increase them, it will turn to a more precise, but demanding, calculation. And I can't remember now what are that 0 0 0 and 1 1 1.

When diving into SCF output files, it's essential to grasp the file format and leverage tools like Gaussian View or ChemCraft. You'll want to focus on key sections such as optimization, vibrational analysis, and thermodynamic properties. From there, visualize the molecular structure, analyze energy trends, and identify vibrational modes.

Ricardo Tadeu Maia Thank you for your valuable answer. After installing xcrysden (version-1.5.60) in Linux fedora, I am encountering an application error: couldn't change working directory to n/xc_

How to resolve this

Prakash Yadav Thank You Prakash for your valuable answer.

what is k_points {crystal_b } format in bands calculation?

4

gG 20

X 20

M 20

gG 20

Can I specify the k_points as shown above?

K_POINTS crystal_b

5

0.0 0.0 0.0 10 ! Gamma point

0.5 0.0 0.0 20 ! X

0.5 0.5 0.0 20 ! M

0.0 0.0 0.0 20 ! Gamma

0.0 0.5 0.5 20 ! I hope this will work; otherwise, get help from online materials clouds like software to generate the k point of material structures.

Prakash Yadav okay, Thank you very much.