excitonic weights

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

Moderators: Davide Sangalli, Daniele Varsano, andrea marini

Post Reply
Posts: 7
Joined: Sat Jul 09, 2016 8:12 am

excitonic weights

Post by 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
Research Scholar
IIIT Allahabad

User avatar
Daniele Varsano
Posts: 2416
Joined: Tue Mar 17, 2009 2:23 pm

Re: excitonic weights

Post by 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

Post Reply