how to calculates the bse on the top GW calculation

Deals with issues related to computation of optical spectra, in RPA (-o c) or by solving the Bethe-Salpeter equation (-o b). Includes local field effects, excitons, etc.

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how to calculates the bse on the top GW calculation

Postby zaabar foudil » Mon Oct 22, 2018 9:55 am

Dear Daniele
How to calculate the bse on the top of the GW calculation ( for mose2 monolayer ). Not that I used the following command line for GWA
../yambo -g n -p p -k hartree -r
after seeing the hbn tutorial. I used the following command line for bse input :
../bin/yambo -o b -p p -k sex -y d -b -r -V all
is it the correct option !
You will find here the GW and bse input files
my best regards
foudil zaabar
university of bejaia
Algeria
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Re: how to calculates the bse on the top GW calculation

Postby Daniele Varsano » Mon Oct 22, 2018 10:02 am

Dear Foudil,

Please note that if you have already the screening in a previous GW calculations using the plasmon pole approximation, you can use it also for the BSE:
yambo -o b -p p -k sex -y d -b -r -V all

This is done correctly by using the -p p option, so no need to calculate also the stating screening (-b) as you already have that information in the ndb.pp databases.

The QP energy are correctly taken into account by this variable:
Code: Select all
KfnQPdb= "E < SAVE/db.QP"              # [EXTQP BSK BSS] Database



Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
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Daniele Varsano
 
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Re: how to calculates the bse on the top GW calculation

Postby zaabar foudil » Mon Oct 22, 2018 9:45 pm

Dear Daniele
I thank you for the quick answer,
I ran the previous calculation (bse) with the following command line ./yambo -o b -k sex -y d -p p -r -V qp
in the case of the GW I corrected 12 bands, 6 occupied and 6 other unoccupied as follows:
% QPkrange # [GW] QP generalized Kpoint / Band indices
1 | 61 | 41 | 52 |
can I use more than 12 corrected bands for constructing the bse matrix !
% BSEBands
41 | 52 | # [BSK] Bands range

my best regards
foudil zaabar
university of bejaia
Algeria
zaabar foudil
 
Posts: 19
Joined: Sun Dec 03, 2017 10:24 am
Location: Algeria

Re: how to calculates the bse on the top GW calculation

Postby Daniele Varsano » Mon Oct 22, 2018 10:23 pm

Dear foudil,

yes you can. Yambo will interpolate the missing QP energies using the values you calculated.
In the report file you will see the results of the interpolation. You will have also an output file contaning the
result of the fit.

Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/
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Daniele Varsano
 
Posts: 1948
Joined: Tue Mar 17, 2009 2:23 pm


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