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High frequency ε_∞ form BSE

Posted: Fri Mar 20, 2026 1:39 pm
by sdwang
Dear all,
Is it possible to obtain high frequency dielectric ε_∞ from BSE results, like alpha?

Thanks!

Shudong

Re: High frequency ε_∞ form BSE

Posted: Mon Mar 23, 2026 8:50 am
by Daniele Varsano
Dear Shudong,

can you be more explicit on what you wish to calculate?

Daniele

Re: High frequency ε_∞ form BSE

Posted: Mon Mar 23, 2026 3:52 pm
by Davide Sangalli
Dear Shudong,
from the literature, high frequency dielectric ε_∞ is referred to as the real part of the electronic dielectric function evaluated at w=0

In case, yes, you can obtain it in yambo at different levels of approximation: IP, RPA, TDDFT, and BSE as well.

Two tips:
a) the convergece w.r.t the number of bands might be rather slow
b) you need to go beyond the resonant approximation.

Best,
D.