evGW

Concerns issues with computing quasiparticle corrections to the DFT eigenvalues - i.e., the self-energy within the GW approximation (-g n), or considering the Hartree-Fock exchange only (-x)

Moderators: Davide Sangalli, andrea.ferretti, myrta gruning, andrea marini, Daniele Varsano

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sdwang
Posts: 287
Joined: Fri Apr 09, 2010 12:30 pm

evGW

Post by sdwang » Tue Sep 26, 2023 1:46 am

Dear developer,
I am just wondering how the evGW results depend on the KS starting point in Yambo code. If the DFT starting point with local or semi-local exchange-correlation functionals gives a very tiny gap or even a semi-metal character, can the evGW overcome these results?

Thanks!

Best

Shudong
Last edited by sdwang on Thu Sep 28, 2023 1:34 am, edited 1 time in total.
S. D. Wang
IMU,HOHHOT,CHINA
E-mail: sdwang@imu.edu.cn

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Daniele Varsano
Posts: 3816
Joined: Tue Mar 17, 2009 2:23 pm
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Re: evGW

Post by Daniele Varsano » Tue Sep 26, 2023 10:25 am

Dear Shudong,

sorry, but I do not understand what you mean.

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/

sdwang
Posts: 287
Joined: Fri Apr 09, 2010 12:30 pm

Re: evGW

Post by sdwang » Fri Oct 13, 2023 7:28 am

Dear developer,
I am just wondering how the evGW results depend on the KS starting point in Yambo code. If the DFT starting point with local or semi-local exchange-correlation functionals gives a very tiny gap or even a semi-metal character, can the evGW overcome these results?

Thanks!

Best

Shudong
S. D. Wang
IMU,HOHHOT,CHINA
E-mail: sdwang@imu.edu.cn

User avatar
Daniele Varsano
Posts: 3816
Joined: Tue Mar 17, 2009 2:23 pm
Contact:

Re: evGW

Post by Daniele Varsano » Fri Oct 13, 2023 8:38 am

Dear Shudong,

to my experience, the evGW mitigate the problem, but it does not solve it completely.
About the opening of the gap, evGW should do the job, but it is something you should check carefully (in some case the self-consistency of the wave function could play an important role).

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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