excitonic weights

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

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excitonic weights

Postby Himani » Wed Dec 13, 2017 8:06 am

Dear sir,

I am trying to understand the excitonic weights output file generated through ypp -e a command. I am not able to understand what "symm." term signifies in the file. Can you please explian me?

Himani Mishra
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IIIT Allahabad
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Re: excitonic weights

Postby Daniele Varsano » Wed Dec 13, 2017 9:12 am

Dear Himani,
The excitonic wave function is defined as \sum_{cvk}Acvk \phi_vk(rh)\phi_ck(re)
rh,re = hole and electron position
|Acvk|^2 is the weight
c,v= conduction, valence bands
k= k point in the full BZ
In Yambo the k sampling in the Irreducible Bz (IBZ) it is expanded in the full Bz (BZ) by using symmetries, so in the output file a k point in the full BZ is expressed by the corresponding k point in the IBZ and the symmetry operation. The symmetry is indicated by an index and the symmetry corresponding to that index can be found in the firsts lines of any report file.


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