First of all, thank you for your help in the previous topic

Actually, we are very interested in the formulas I mentioned in these two topic, and I am trying to understand the the physics behind these parameters. This is also the reason why I am asking these questions.

Allow me to share my understanding, if you don’t mind.

(1) with

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`ypp -e a -b 1 -F ypp_nodipoles.in`

It represents the weights (contributions) at each K-points for a specified excitonic state.

(2) with

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`ypp -e a -b 1 -d exc -F ypp_withdipoles.in`

**In which <e|D|h> is optical matrix elements (‘dipoles’), and the value of dipoles determines whether excitons are bright or dark.**

(3) Considering this equation, I speculate that Aeh should have a similar form to dipole (but as you mentioned, it should be a scalar). We are curious if it’s possible to use Yambopy to read Aeh over the entire Brillouin zone.

Or, Aeh is a real number, and I only need to take the square root of the amplitude in the o-amplitude?

Thanks again for your help