GW+U

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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samaneh
Posts: 165
Joined: Tue Jan 21, 2014 9:03 am

GW+U

Post by samaneh » Sun Nov 09, 2014 8:44 am

Dear Developers,
1-Is that possible to perform GW calculation with yambo,
using the results of GGA+U calculation of espresso ?
2- If the PBE functional could not indicate the midgap states
(localized states of doped structure) in dos or bandstructure,
is it possible that GW calculation present them,
or can we observe these localized states in midgap??
Thanks
S. Ataei, University of Tehran, Iran
S. Ataei, PhD student at University of Tehran, Iran.

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Daniele Varsano
Posts: 3835
Joined: Tue Mar 17, 2009 2:23 pm
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Re: GW+U

Post by Daniele Varsano » Sun Nov 09, 2014 4:53 pm

Dear S. Atei,
actually it is not possible to do this kind of calculations.
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/

samaneh
Posts: 165
Joined: Tue Jan 21, 2014 9:03 am

Re: GW+U

Post by samaneh » Mon Nov 10, 2014 11:46 am

Dear Daniele,
Thanks for your reply.
But what about the second question??
S. Ataei, PhD student at University of Tehran, Iran.

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Daniele Varsano
Posts: 3835
Joined: Tue Mar 17, 2009 2:23 pm
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Re: GW+U

Post by Daniele Varsano » Mon Nov 10, 2014 12:09 pm

Dear Samaneh,
your second question it is not a question related to the code, and I suggest you to discuss with your colleagues and advisors.
My suggestion anyway is always to have in mind that GW approximation is not a magic wand and especially it is a perturbation theory, so if your starting point (ground state) is far away from the right description, it hardly can gives you the right answer. But, again, I'm not familiar with the topic you are studying so take my advice as a general consideration and discuss it with your coworkers.

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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