## 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.

Moderators: Davide Sangalli, andrea marini, Daniele Varsano

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

Dear Alan,
actually, it is not very clear to me what your doubts are.
In presence of SO coupling your valence and condition wfs are represented with 2-components spinor.
You can still fix (o integrate) an hole in the valence wfs, and the total excitonic wave function in this case is obtained by summing up the two components.

Again, it is possible I have misinterpreted your question.
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
Posts: 98
Joined: Thu Jul 02, 2020 3:56 pm

### Re: Calculating probability exciton is in a specific region

Dear Daniele

Apologies, I am probably not making myself clear (or getting confused!).

For example, if the two conduction band spinor components are the opposite of each other (i.e. +A(r) and -A(r)), then am I right in saying that there would be a cancellation in the calculation where the hole is fixed in some position?

All the best,

Alan
Alan Bowman
University of Cambridge

Daniele Varsano
Posts: 2719
Joined: Tue Mar 17, 2009 2:23 pm
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### Re: Calculating probability exciton is in a specific region

Dear Alan,
I would say only if the two components of the valence bands are the same.

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
Posts: 98
Joined: Thu Jul 02, 2020 3:56 pm

### Re: Calculating probability exciton is in a specific region

Dear Daniele

That's really useful, thank you very much!

Best wishes,

Alan
Alan Bowman
University of Cambridge

arb83@cam.ac.uk
Posts: 98
Joined: Thu Jul 02, 2020 3:56 pm

### Re: Calculating probability exciton is in a specific region

Dear Daniele

I hope you're doing well. Could I ask what the input line should be used to generate the static dielectric screening for a BSE calculation in yambo 5? I tried '-X s' but am receiving some MPI errors, so want to double check I'm using the code properly.

With best wishes,

Alan
Alan Bowman
University of Cambridge

Daniele Varsano
Posts: 2719
Joined: Tue Mar 17, 2009 2:23 pm
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### Re: Calculating probability exciton is in a specific region

Dear Alan,
yes, that's the correct option. MPI error sounds strange, you should launch the input generation in serial mode, or using "mpirun -n 1" or alike.
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/

claudio
Posts: 320
Joined: Tue Mar 31, 2009 11:33 pm
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### Re: Calculating probability exciton is in a specific region

Dear Alan,

just an additional comment, try to the option -nompi
when you generate the input

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