[Wien] Continuing confusion in dos...

[Gavin Abo]

There is the following, but maybe it will not help since it is just a 
list of links to previous posts already given in the mailing list.

At [1], it advises to use "at least one iteration".

In your post at [2] if I have interpreted it correctly, you have a 3D 
structure (cubic spinel supercell with 56 atoms).

With regards to your 2x2x1 k-mesh, I have seen k-meshes, such as 3x3x1 
[3], with 1 k-point in the z-direction like that used for 2D structures 
[modeled in 3D as a supercell with vacuum (which might also go by the 
names surface [4], slab, or monolayer)].  Though, maybe more than 1 
k-point in the z-direction is need for some 3D structures.

Post at [5] mentions a 2x2x2 is a fine start.  Then, from there you 
could increase the k-mesh (e.g., 3x3x3, ..., 5x5x5, ...) for k-point 
convergence testing.

In post [6], it looks like 6x6x6 was a k-mesh were k-point convergence 
was being reached in many cases.

It also looked like in [7] for DOS with -hf that it could be important 
that convergence testing had been done with nband in case.inhf.

[1] 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg20756.html
[2] 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg21511.html
[3] 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg21083.html
[4] Slide 29 titled "Surfaces": 
http://susi.theochem.tuwien.ac.at/events/ws2006/WIEN2k-getting_started.pdf
[5] 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg20861.html
[6] 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg20384.html
[7] 
https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg21069.html

On 11/28/2021 10:47 PM, shamik chakrabarti wrote:
> Dear Dr. Tran,
>
>                  I have applied 4k points using the procedure as you 
> have suggested. However, for one iteration with 4k points, it is 
> coming as "the energy in scf is not converged". Also, the DOS looks 
> different from 1 k points. I am attaching two plots here. Is it that, 
> to get the correct DOS we have to run more than one iteration 
> until the energy is converged?
>
> Looking forward to your suggestions in this regard.
>
> with regards,