Calculating probability exciton is in a specific region

Anything regarding the post-processing utility (e.g. excitonic wavefunction analysis) is dealt with in this forum.

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arb83@cam.ac.uk
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Re: Calculating probability exciton is in a specific region

Post by arb83@cam.ac.uk » Thu Nov 12, 2020 1:01 pm

Perfect, thank you!
Alan Bowman
University of Cambridge

arb83@cam.ac.uk
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Re: Calculating probability exciton is in a specific region

Post by arb83@cam.ac.uk » Tue Jan 05, 2021 1:51 pm

Dear Daniele

Happy New Year to you!

Is there any news on when the next version of Yambo will be released?

Best wishes,

Alan
Alan Bowman
University of Cambridge

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Daniele Varsano
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Re: Calculating probability exciton is in a specific region

Post by Daniele Varsano » Tue Jan 05, 2021 4:01 pm

Dear Alan,
even if the new version has been not yet officially released you can download it at the following address:

https://github.com/yambo-code/yambo

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/

arb83@cam.ac.uk
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Re: Calculating probability exciton is in a specific region

Post by arb83@cam.ac.uk » Tue Jan 05, 2021 6:31 pm

Dear Daniele

Hugely appreciated, thank you!

Best wishes,

Alan
Alan Bowman
University of Cambridge

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Re: Calculating probability exciton is in a specific region

Post by arb83@cam.ac.uk » Thu Jan 07, 2021 12:57 pm

Dear Daniele

I'm assuming the master version corresponds to version 5, but if this isn't the case please do let me know.

All the best,

Alan
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University of Cambridge

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Daniele Varsano
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Re: Calculating probability exciton is in a specific region

Post by Daniele Varsano » Thu Jan 07, 2021 1:15 pm

Dear Alan,
yes, indeed this is the case.

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/

arb83@cam.ac.uk
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Re: Calculating probability exciton is in a specific region

Post by arb83@cam.ac.uk » Fri Jan 08, 2021 12:22 pm

Dear Daniele

I have now downloaded yambo version 5, thank you for this.

The new analysis tool has thrown up one additional issue in visualising excitonic wavefunctions, which I think you may be able to advise on. I have been looking at an interface between two materials. Looking at the first excitonic state, I have calculated the average electron and average hole positions (using the new version of ypp). Both electron and hole are fully localised on only one side of the interface (which is what I expect to observe in this simulation). However, if I try to visualise the exciton with the hole fixed in a specific position (where it has high probability of being, based on its average position), the resulting electron density is on the other side of the interface. This holds if I put the hole in several different positions, so there is some kind of contradiction here. Do you have any suggestions on whether this could be something to do with the post processing?

I should note that these simulations are within the context of spin-orbit coupling, so when I fix the hole I do not know if I am looking at one spinor component or fixing spins in some way. The state I am looking at is in an organic molecule, so is a triplet state, hence why this could be of note. When I carry out equivalent simulations without spin-orbit coupling there is no contradiction between the average electron/hole positions, and the excitonic state with fixed hole position.

With best wishes,

Alan
Alan Bowman
University of Cambridge

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claudio
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Re: Calculating probability exciton is in a specific region

Post by claudio » Fri Jan 08, 2021 12:32 pm

Dear Alan

this can be simply a bug in the electron/hole variable name
in the new input file for the electron/hole density

I will check and fix it if it is the case, anyway all plots are correct

for the definition of electron and hole density you can look here

http://www.yambo-code.org/wiki/index.ph ... mbo_5.x.29

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
Freely download scientific books from: http://www.freescience.info

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Re: Calculating probability exciton is in a specific region

Post by Daniele Varsano » Fri Jan 08, 2021 12:46 pm

Dear Alan,
I do not have an answer.
What I can suggest you, when placing the hole, look first at the real-space valence wave functions participating to the excitation and judge from there
where there is an high probability to find an hole. Maybe Claudio, who implemented this new feature, can tell you more on that.

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/

arb83@cam.ac.uk
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Re: Calculating probability exciton is in a specific region

Post by arb83@cam.ac.uk » Fri Jan 08, 2021 12:56 pm

Dear Claudio

I'm afraid I don't understand your comments regarding a bug? Also, the page you send doesn't detail how these quantities are dealt with when spin orbit coupling is included.

I have two sets of contradictory results (one says both electron and hole are in 'region 1', the other that the electron is in 'region 1' and the hole in 'region 2'), so there is a problem somewhere.

All the best,

Alan
Alan Bowman
University of Cambridge

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