GW yambo error

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

User avatar
hammouri
Posts: 34
Joined: Fri Feb 09, 2018 11:25 pm

Re: GW yambo error

Post by hammouri » Sat Apr 09, 2022 3:30 pm

Thank you, Daniele!
If the indirect band gap is located at two different points, say between 1 and 49. When I run convergence calculations, for which k point I should make graphs? Is it 1, 49, or the full range from 1-49.
Also, in the output below, the indirect band gap location is different from DFT and Hartree. See below:

Code: Select all

  [X] Direct Gap                                    :  2.479373 [eV]
  [X] Direct Gap localized at k-point               :  1
  [X] Indirect Gap                                  :  1.590475 [eV]
  [X] Indirect Gap between k-points                 :   80    1
  [Hartree-Fock] Direct Gap                         :  10.40613 [eV]
  [Hartree-Fock] Direct Gap localized at k-point    :  1
  [Hartree-Fock] Indirect Gap                       :  7.446659 [eV]
  [Hartree-Fock] Indirect Gap between k-points      :   49    1
Hammouri, M.
Assistant Professor of Physics
University of Wisconsin
USA

User avatar
Daniele Varsano
Posts: 3773
Joined: Tue Mar 17, 2009 2:23 pm
Contact:

Re: GW yambo error

Post by Daniele Varsano » Sat Apr 09, 2022 10:07 pm

Dear Hammouri,

in order to compare the gaps between DFT and HF you need to calculate the correction for all the k points.
Next convergence tests can be done by looking at the gap in few k points (e.g. direct gap at gamma points and indirect gap).

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/

Post Reply