e-h contribution threshold for reciprocal wavefunction

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xueshanxihua
Posts: 18
Joined: Tue Dec 06, 2016 9:43 am

e-h contribution threshold for reciprocal wavefunction

Post by xueshanxihua » Fri Dec 28, 2018 2:31 pm

Dear all,

By 'ypp -e a' command, one can create 'exc_weight_at_N' file containing reciprocal distribution of certain exciton state N. Just as follows:

# Electron-Hole pairs that contributes to Excitonic State 1 more than 5%
#
# K-point [iku] Weight
# 0.00000 0.00000 0.00000 0.06555
# 0.00000 0.08333 0.00000 0.41202
# 0.000000 0.166667 0.000000 0.449042
......

However, as noted in the file, it only include "Electron-Hole pairs that contributes to Excitonic State 1 more than 5%". So can I reduce or choose this threshold 5% by input or by modifying the source code?

Thanks a lot for any help~
Zeyu Jiang
Postdoc
Department of Physics, Applied Physics, and Astronomy
Rensselaer Polytechnic Institute
Troy, New York

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Daniele Varsano
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Re: e-h contribution threshold for reciprocal wavefunction

Post by Daniele Varsano » Fri Dec 28, 2018 4:52 pm

Dear Zeyu Jiang,
the input variable MinWeight controls the threshold.
The default is MinWeight=0.01 corresponding to a threshold of 5%, if you change this variable the threshold will be Minweight*5.
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/

xueshanxihua
Posts: 18
Joined: Tue Dec 06, 2016 9:43 am

Re: e-h contribution threshold for reciprocal wavefunction

Post by xueshanxihua » Sat Dec 29, 2018 9:06 am

Daniele Varsano wrote:Dear Zeyu Jiang,
the input variable MinWeight controls the threshold.
The default is MinWeight=0.01 corresponding to a threshold of 5%, if you change this variable the threshold will be Minweight*5.
Best,

Daniele
Thanks a lot for your answer, Dear Daniele.

By the way, the shown weight on certain k point is the summation of all its symmetry equivalent k points in the full BZ, is it?
Zeyu Jiang
Postdoc
Department of Physics, Applied Physics, and Astronomy
Rensselaer Polytechnic Institute
Troy, New York

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Daniele Varsano
Posts: 3816
Joined: Tue Mar 17, 2009 2:23 pm
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Re: e-h contribution threshold for reciprocal wavefunction

Post by Daniele Varsano » Sat Dec 29, 2018 9:19 am

By the way, the shown weight on certain k point is the summation of all its symmetry equivalent k points in the full BZ, is it?
Yes it is, only k points in the IBZ are reported. Detailed weights for each transition, k_point and symmetry operation are reported just below. Note that the symmetry operation is indicated by an index. The corresponding symmetry operation matrix is reported in each of the yambo report files.

Note also that degenerate excitons are grouped, so that the weight is equal to the degeneracy. The threshold for considering exciton degenerate can be controlled by input.

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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