When SLEPC solver used for BSE, ypp fails to return exciton composition in terms of one-body states

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aseemrajan
Posts: 8
Joined: Mon Nov 18, 2019 11:44 am

When SLEPC solver used for BSE, ypp fails to return exciton composition in terms of one-body states

Post by aseemrajan » Mon Oct 18, 2021 12:33 pm

Dear Yambo developers,

I used SLEPC solver for the BSE and tried to compute the exciton composition of bulk Si in terms of one-body Kohn-Sham states using ypp. Ypp returned an error as following:

Code: Select all

[ERROR] STOP signal received while in[06] Excitonic Properties @ Q-index #1
[ERROR] ndb.BS_diago not found
Please note that contrary to the error message, the ndb.BS_diago is present and ypp works well to return the BSE eigenvalues sorted with respect to energy and amplitude or to print the spatial distribution of exciton wavefunction.
The input that I used for ypp to obtain the exciton composition is as follows:

Code: Select all

excitons                         # [R] Excitonic properties
amplitude                        # [R] Amplitude
States= "1 - 2"                  # Index of the BS state(s)
BSQindex= 1                      # Q-Index of the BS state(s)
#DipWeight                     #  Weight the contribution to the exciton WFs with the dipoles
Degen_Step= 0.010000       eV    # Maximum energy separation of two degenerate states
Please also note that ypp works well for above input when BSE is solved by diagonalization instead of SLEPC.

Please suggest ways to get around the error for ypp in case of SLEPC approach.
Thank you very much in advance!

Kind regards,
Aseem
Aseem Rajan Kshirsagar,
Postdoctoral researcher,
Department of Physics and Material Science,
University of Luxembourg (Limpertsberg campus)

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Davide Sangalli
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Re: When SLEPC solver used for BSE, ypp fails to return exciton composition in terms of one-body states

Post by Davide Sangalli » Mon Oct 18, 2021 1:30 pm

Dear Aseem,
can you attach the report file of the two yambo runs, i.e. the one with the slepc solver and the one with the diago solver.

ypp (if you are using the last version) should generate a report as well.
Also in such case, can you attach the report of the two ypp runs (the one after diagonalization and the one after slepc)

Best,
D.
Davide Sangalli, PhD
CNR-ISM, Division of Ultrafast Processes in Materials (FLASHit) and MaX Centre
https://sites.google.com/view/davidesangalli
http://www.max-centre.eu/

aseemrajan
Posts: 8
Joined: Mon Nov 18, 2019 11:44 am

Re: When SLEPC solver used for BSE, ypp fails to return exciton composition in terms of one-body states

Post by aseemrajan » Mon Oct 18, 2021 3:47 pm

Dear Davide,

Thank you for your quick reply.
It is working fine now.
The problem was probably occurring due to mismatch in yambo versions used for BSE calculation and post processing.

Have a nice day.

Thanks,
Aseem
Aseem Rajan Kshirsagar,
Postdoctoral researcher,
Department of Physics and Material Science,
University of Luxembourg (Limpertsberg campus)

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