Dear all,
I have solved the BSE at finite temperature with Yambo and referred to the following silicon example: http://www.yambo-code.org/wiki/index.ph ... emperature I Noticed that it changed the BSE type to "coupling" in this tutorial and many exciton with negative energy after typed "ypp_ph -e s". But when I change BSEmod to" retarded", the exciton energy becomes positive, which is what I want. Does BSEmod have to be set as coupling after considering Electron Phonon Coupling? Is "KfnQP_E" the GW difference between considering and not considering Electron Phonon Coupling?
The problems of Bethe-Salpeter at finite temperature
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The problems of Bethe-Salpeter at finite temperature
yifei liu
PhD student
Beijing Institute of Technology,China
PhD student
Beijing Institute of Technology,China
- Daniele Varsano
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Re: The problems of Bethe-Salpeter at finite temperature
Dear Shan Dong,
when adding the coupling you have both resonant and antiresonant part of the matrix and this what negative energies applies in the spectrum. When discarding the coupling (Tamm-Dancoff) only the resonant part is solved as the antiresonant spectrum is exactly the negative of the resonant one.
Here you need to use the coupling as stated:
"Notice that we changed the BSE type to "coupling" because you need the full Bethe-Salpeter to deal with complex quasi-particles."
In general, KfnQP_E should be the energy correction to mimic the GW correction.
Best,
Daniele
when adding the coupling you have both resonant and antiresonant part of the matrix and this what negative energies applies in the spectrum. When discarding the coupling (Tamm-Dancoff) only the resonant part is solved as the antiresonant spectrum is exactly the negative of the resonant one.
Here you need to use the coupling as stated:
"Notice that we changed the BSE type to "coupling" because you need the full Bethe-Salpeter to deal with complex quasi-particles."
In general, KfnQP_E should be the energy correction to mimic the GW correction.
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/
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/
- claudio
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Re: The problems of Bethe-Salpeter at finite temperature
Dear Shan Dong
there is the possiblity to use resonant BSE at finite temperture, by means of the inversion solver.
I just updated the tutorial:
http://www.yambo-code.org/wiki/index.ph ... emperature
best
Claudio
there is the possiblity to use resonant BSE at finite temperture, by means of the inversion solver.
I just updated the tutorial:
http://www.yambo-code.org/wiki/index.ph ... emperature
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
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com
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- Posts: 48
- Joined: Thu Oct 17, 2019 5:26 am
Re: The problems of Bethe-Salpeter at finite temperature
Dear Claudio,claudio wrote: ↑Fri Apr 30, 2021 2:55 pm Dear Shan Dong
there is the possiblity to use resonant BSE at finite temperture, by means of the inversion solver.
I just updated the tutorial:
https://www.yambo-code.org/wiki/index.p ... emperature
best
Claudio
Thanks for your patience, I use the yambo 5.0.2, i have used resonant BSE by typing" yambo_ph -X s -o b -k sex -y i -V qp" but when i typed " ypp_ph -e s" to get the exciton energy
Code: Select all
<---> [01] MPI/OPENMP structure, Files & I/O Directories
<---> [02] Y(ambo) P(ost)/(re) P(rocessor)
<---> [03] Core DB
<---> :: Electrons : 8.000000
<---> :: Temperature : 0.000000 [eV]
<---> :: Lattice factors : 5.132000 5.132000 5.132000 [a.u.]
<---> :: K points : 8
<---> :: Bands : 12
<---> :: Symmetries : 48
<---> :: RL vectors : 9257
<---> [04] K-point grid
<---> :: Q-points (IBZ): 1
<---> :: X K-points (IBZ): 8
<---> [05] CORE Variables Setup
<---> [05.01] Unit cells
<---> [05.02] Symmetries
<---> [05.03] Reciprocal space
<---> [05.04] K-grid lattice
<---> Grid dimensions : 4 4 4
<---> [05.05] Energies & Occupations
<---> [06] Excitonic Properties @ Q-index #1
[ERROR] STOP signal received while in[06] Excitonic Properties @ Q-index #1
[ERROR] ndb.BS_diago not found
If i changed the BSEmod variable to retarded and changed the BSSmod variable to d , Things seem to ok. In the tutorial you mentioned above,"we also introduce an additional rigid shift of 0.8 eV to mimic the GW correction with the line 0.500000 | 1.000000 | 1.000000 | \# [EXTQP BSK BSS] E parameters (c/v) eV|adim|adim." I wonder why the value of KfnQP_E is 0.5 instead of 0.8.
yifei liu
PhD student
Beijing Institute of Technology,China
PhD student
Beijing Institute of Technology,China
- claudio
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- Joined: Tue Mar 31, 2009 11:33 pm
- Contact:
Re: The problems of Bethe-Salpeter at finite temperature
Dear Shan Dong
thank you for find the typos in the tutorial it was 0.5 in both the input and the explanation I corrected it.
Regarding the inversion solver, as specified in the tutorial (now in a better way), if you use the inversion solver
you cannot analyse the excitons you just get the spectra
best
Claudio
thank you for find the typos in the tutorial it was 0.5 in both the input and the explanation I corrected it.
Regarding the inversion solver, as specified in the tutorial (now in a better way), if you use the inversion solver
you cannot analyse the excitons you just get the spectra
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
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com