How to specify the q range for exciton band structures

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sdwang
Posts: 287
Joined: Fri Apr 09, 2010 12:30 pm

How to specify the q range for exciton band structures

Post by sdwang » Sun Jul 17, 2022 8:35 am

Dear all,
I want to get the excitons band structures at finite momentum q, and how to specify the range of the q in ypp input? (>ypp -e i gives the input as below:

Code: Select all

#
excitons                         # [R] Excitonic properties
interpolate                      # [R] Interpolate
INTERP_mode= "BOLTZ"             # Interpolation mode (NN=nearest point, BOLTZ=boltztrap aproach)
INTERP_Shell_Fac= 20.00000       # The bigger it is a higher number of shells is used
INTERP_NofNN= 1                  # Number of Nearest sites in the NN method
BANDS_steps= 100                 # Number of divisions
cooIn= "rlu"                     # Points coordinates (in) cc/rlu/iku/alat
cooOut= "rlu"                    # Points coordinates (out) cc/rlu/iku/alat
States= "1 - 1"                  # Index of the BS state(s)
BSQindex= 1                      # Q-Index of the BS state(s)
%BANDS_kpts                      # K points of the bands circuit
 0.000000| 0.000000| 0.000000|
 0.333333| 0.333333| 0.000000|
%
where there is no option for specifying the q range.

Thanks!

Yaning
S. D. Wang
IMU,HOHHOT,CHINA
E-mail: sdwang@imu.edu.cn

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Davide Sangalli
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Re: How to specify the q range for exciton band structures

Post by Davide Sangalli » Sun Jul 17, 2022 3:09 pm

First you have to solve the BSE for all the q points available.

Then you just need to specify the path.
The variable is

Code: Select all

%BANDS_kpts                      # K points of the bands circuit
 0.000000| 0.000000| 0.000000|
 0.333333| 0.333333| 0.000000|
%
but it means the path in Q-space

https://www.yambo-code.eu/wiki/index.ph ... Yambo_5.x)

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/

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