GW bands get tangled up

Run-time issues concerning Yambo that are not covered in the above forums.

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Daniele Varsano
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Re: GW bands get tangled up

Post by Daniele Varsano » Tue Nov 17, 2020 11:59 am

Dear Ying Chen,
it seems to me that you have very different corrections for some occupied states, see e.g. at gamma:
you have positive or negative correction depending on the bands (negative for the deeper and positive for the others). For other k points you are in a different situation e.g. k=59, nearly degenerate bands (69 and 70),
one with a positive and one with a negative correction (see below). I suspect that this makes different band crossing at GW level.

Before looking at the interpolated bands I suggest you inspect your GW energies, I suspect that also the bands extracted from the calculated points will have similar problems.

From the report file, I can see you are using pseudopotential with Non-linear core corrections. I suggest you to use pseudopotential without NLCC (e.g. sg15 set), or if you want to use pseudo with NLCC you need to activate in the input file the flag:

Code: Select all

UseNLCC
.
It appears in the input file when creating files with high verbosity (-V all) and you need to uncomment it.
If you want to try this, you need to delete the ndb.HF* and ndb.QP file and repeat your calculation (you can keep the ndb.pp file as this is not affected by the nlcc).

Best,
Daniele



Gamma:
# K-point Band Eo E-Eo Sc|Eo

1.00000 67.00000 -1.11448 -0.33846 1.51109
1.00000 68.00000 -1.11448 -0.33827 1.51108
1.00000 69.00000 -0.76919 0.29526 1.53658
1.00000 70.00000 -0.76919 0.29494 1.53658
1.00000 71.00000 -0.37559 0.27921 1.41679
1.00000 72.00000 -0.37559 0.27965 1.41679

K= 0.142857 0.238095 0.000000 (rlu)
59.00000 67.00000 -1.85707 -0.82703 2.21691
59.00 68.00 -1.760 0.4978E-2 2.148
59.00000 69.00000 -1.67270 -0.52412 2.06564
59.00000 70.00000 -1.64314 0.44321 2.10633
59.00000 71.00000 -1.11250 -0.14020 1.77366
59.00000 72.00000 -0.80520 -0.07430 1.58187
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/

YChen
Posts: 15
Joined: Wed Apr 14, 2021 2:55 am

Re: GW bands get tangled up

Post by YChen » Tue Jun 08, 2021 11:53 am

Dear Dr. Daniele,

Sorry for the late reply. I have indeed found the problem you mentioned, but I have carried out the convergence analysis of the parameters used in the calculation according to the tutorial, so I don't know how to solve this problem.

Best,
Ying Chen
Ying Chen
Academy for Engineering and Technology, Fudan University, Shanghai 200433, China

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claudio
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Re: GW bands get tangled up

Post by claudio » Tue Jun 08, 2021 1:32 pm

Dear Ying Chen,

I see from you report files that you are using the 4.5.1 version of Yambo, please update it to the last version

https://github.com/yambo-code/yambo/wik ... -format%29

because a bug it was corrected that gave noise/tnagled bands in GW

best
Claudio
Claudio Attaccalite
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com

YChen
Posts: 15
Joined: Wed Apr 14, 2021 2:55 am

Re: GW bands get tangled up

Post by YChen » Wed Jun 09, 2021 2:50 am

Dear Claudio,

Thank you for your reply! Is the bug you mentioned corrected in Yambo.5.0.3? I calculated the GW band using Yambo.5.0.1, and the same tnagled band was obtained.

Best,
Ying Chen
Ying Chen
Academy for Engineering and Technology, Fudan University, Shanghai 200433, China

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claudio
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Re: GW bands get tangled up

Post by claudio » Wed Jun 09, 2021 10:20 am

Dear Ying Chen

the bug was corrected in the 5.0.1 version, so your calculations should be fine,

plese put your DFT and Yambo inputs, so we can try to reproduce it

best
Claudio
Claudio Attaccalite
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com

YChen
Posts: 15
Joined: Wed Apr 14, 2021 2:55 am

Re: GW bands get tangled up

Post by YChen » Thu Jun 10, 2021 3:22 am

Dear Claudio,

I have put the input files in the attached file, thank you!

Best,
Ying Chen
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Ying Chen
Academy for Engineering and Technology, Fudan University, Shanghai 200433, China

YChen
Posts: 15
Joined: Wed Apr 14, 2021 2:55 am

Re: GW bands get tangled up

Post by YChen » Thu Jun 10, 2021 11:47 am

Dear Claudio,

I have a new problem when I used YAMBO-5.0.1 to calculate the quasi-particle band structure of two-dimensional materials. The calculation is aborted without any error. I have put the input and output files in the attached file, thank you!

Best,
Ying Chen
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Ying Chen
Academy for Engineering and Technology, Fudan University, Shanghai 200433, China

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Daniele Varsano
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Re: GW bands get tangled up

Post by Daniele Varsano » Thu Jun 10, 2021 11:56 am

Dear Ying Chen,

according to your report you have 78 filled bands.

Code: Select all

[X] Filled Bands                                  :   78
[X] Empty Bands                                   :   79  120
When calculating the response function and GW self energy you need to include empty bands others no transitions are included.
So the values for BndsRnXp and GbndRnge are not appropriate and the codes stop when calculating dipoles as there are not <c|r|v> states to compute.

Code: Select all

% BndsRnXp
   1 | 20 |                         # [Xp] Polarization function bands
%

Code: Select all

% GbndRnge
   1 | 30 |                         # [GW] G[W] bands range
%
Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/

YChen
Posts: 15
Joined: Wed Apr 14, 2021 2:55 am

Re: GW bands get tangled up

Post by YChen » Sat Sep 25, 2021 12:01 pm

Dear Claudio,

As for the problem of band crossing, I have uploaded the input files. Could you help me check them if you have time? thank you!

Best,
Ying Chen
Ying Chen
Academy for Engineering and Technology, Fudan University, Shanghai 200433, China

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Daniele Varsano
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Re: GW bands get tangled up

Post by Daniele Varsano » Sat Sep 25, 2021 4:58 pm

Dear Ying ,
can you describe better your problem and attach your yambo input/report files as well as ypp input file?

Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/

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