Yambo Community Forum

Dear Developers,

We are using YAMBO to calculate the contributions of a series of Electron-Hole pairs to some specific exciton. But the output file just lists the Electron-Hole pairs with the K points symmetrized by the crystal symmetry. Is it possible to output the full K points in the 1st BZ without symmetrization? Thank you!

Best regards,
Hao Zhang

Dear Hao Zhang,

You cannot access directly the full BZ, anyway in the output you have the k in the IBZ and the symmetry index.
The corresponding symmetry operations are reported at the beginning of the report so you need jut to apply the simmetry operations to the specific k point in the IBZ.

Best,
Daniele

Dear Daniele,

Thank you! When calculating the lifetime for excitons, the output includes 'Kv-q ibz Symm_kv'. What is the difference between 'Kv-q ibz' and 'Symm_kv'?

Hao

Daniele Varsano wrote: ↑Tue Jun 09, 2020 4:25 pm Dear Hao Zhang,

You cannot access directly the full BZ, anyway in the output you have the k in the IBZ and the symmetry index.
The corresponding symmetry operations are reported at the beginning of the report so you need jut to apply the simmetry operations to the specific k point in the IBZ.

Best,
Daniele

Dear Hao,
in your attachment, I can see an input/output for a real-axis GW calculation which contains quasi-particle lifetime.
In the results of the BSE diagonalization o*weight you have the excitonic wavefunction defined as i.e.
|exc>=\sum_cvk Avck \psi_ck(r_e)\psi_vk(r_h)

where r_e and r_h are electron and hole positions. Acvk the eigenvector of the BSE (|Acvk|^2 is the weight).
In the output:
(Kv-q ibz , Symm_kv ) provides you the K point in the BZ as kin in the IBZ and its associated symmetry. Note that transferred momentum (q) is zero.
The output is thought also for considering finite momentum BSE that at the moment it is not included in the GPL release of the code.

Best,
Daniele

Dear Hao

you can have a look at this script that projects the electron-hole contribution
along with the band structure. I think you can change the script to project
the electron-hole contribution on any k-point you like.

http://www.yambo-code.org/wiki/index.ph ... ocal_space

best
Claudio