cross section

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malwi
Posts: 36
Joined: Mon Feb 29, 2016 1:00 pm

cross section

Post by malwi » Sat Apr 13, 2024 11:18 am

Dear Yambo Team and Users,

I am a bit confused with the definition of the cross section (sigma) versus the oscillator strength (f).
Since I cannot find it on Yambo forum, I found it on Octopus website:
they describe it in the TDDFT output by

f = mc / [ 2pi^2 * (Planc/2pi)^2 ] * sigma
https://www.octopus-code.org/documentat ... opagation/

But the Planc constant is proportional to kg*m/s,
thus, in my opinion,
either there is (mc)^2 or there is (Planc/2pi)^1 and not "Planc square".
Because "square" in Planc gives additional "kg" in this formula.

Do you know any Yambo publication about this?

Second question: is this definition the same for all dimensionalities: 3D, 2D, 1D, 0D?

Thank you very much,
Gosia
dr hab. Małgorzata Wierzbowska, Prof. IHPP PAS
Institute of High Pressure Physics Polish Academy of Sciences
Warsaw, Poland

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