RPA absorption spectrum analysis for spin polarized system

Deals with issues related to computation of optical spectra in reciprocal space: RPA, TDDFT, local field effects.

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RPA absorption spectrum analysis for spin polarized system

Post by nthiliniek » Fri Apr 19, 2024 9:25 pm


I am interested in analyzing the optical spectrum of RPA level. I have tried to run a calculation in e-h space for a spin-polarized system. However, I am not sure about defining BSE bands in the input, since I have different occupied/unoccupied band ranges for spin-up channel and the spin-down channel.

According to the report file:
[X] === Spin up channel ===
[X] Conduction Band Min [spin UP]: 0.471598 [eV]
[X] Valence Band Max [spin UP]: 0.000000 [eV]
[X] Filled Bands [spin UP]: 290
[X] Empty Bands [spin UP]: 291 345
[X] === Spin dn channel ===
[X] Conduction Band Min [spin DN]: 0.473750 [eV]
[X] Valence Band Max [spin DN]: -0.071480 [eV]
[X] Filled Bands [spin DN]: 286
[X] Empty Bands [spin DN]: 287 345
Is there a way to define the bands separately for two channels? If not, how do I select a common combination for both channels? Here I am attaching my input file and the report file.
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Niranji Ekanayake
PhD Candidate
Department of Chemistry
Queen's University
Kingston, ON K7L 3N6

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Daniele Varsano
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Joined: Tue Mar 17, 2009 2:23 pm

Re: RPA absorption spectrum analysis for spin polarized system

Post by Daniele Varsano » Sun Apr 21, 2024 4:55 pm

Dear Niranji,

Unfortunately, is not possible to indicate different bands for separate channels, so you need to specify a range of bands where you have occupied and empty bands from both channels. The range indicated in the input file is correct, next you will need to verify if they are enough to get converged results.

Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale

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