Yambo Community Forum

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~

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

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?

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