Yambo Community Forum

Dear all:
I noticed that there is a Extendout option in mailing list but I cannot find it in the variable page. Is it deleted in recent versions (3.4.1)?
What I want to extract from the output is the component of optical spectra so that I can identify the origin of the peaks in the obtained optical spectra. For example, is it possible to distinguish the contribution from state S1 to state S2? Thank you!


Shijun Zhao
Peking University

Dear Shijun,
the Extendout option is still available and you can activate it by using the option when preparing input file. Anyway it gives just more information on the GW calculation in the output, and this is not what you are looking for.
The contribution of the optical spectra can be identified in a BSE calculation or in a TDDFT (when calculated in real space), option: you can then look at them using the postprocessing analyzer ypp: after having sorted them by increasing energies (ypp -e s).
in order to look at the component you need to activate the WRbsWF flag in the input when diagonalizing the matrix.
Anyway please note that if you want to see the offset (energy of the first excitation) you need to look at the eigenvalues simply using
(ypp -e s) option and not at the component of the optical spectra as different transition can mix, unless you are doing independent particle calculations.
Hope it helps,
Best,
Daniele

Daniele Varsano wrote:Dear Shijun,
the Extendout option is still available and you can activate it by using the

Code: Select all

-V qp

option when preparing input file. Anyway it gives just more information on the GW calculation in the output, and this is not what you are looking for.
The contribution of the optical spectra can be identified in a BSE calculation or in a TDDFT (when calculated in real space), option:

Code: Select all

yambo -o b -k ...

you can then look at them using the postprocessing analyzer ypp:

Code: Select all

ypp -e a

after having sorted them by increasing energies (ypp -e s).
in order to look at the component you need to activate the WRbsWF flag in the input when diagonalizing the matrix.
Anyway please note that if you want to see the offset (energy of the first excitation) you need to look at the eigenvalues simply using
(ypp -e s) option and not at the component of the optical spectra as different transition can mix, unless you are doing independent particle calculations.
Hope it helps,
Best,
Daniele

Thank you very much for your reply!
Is there any method to dig out such information in RPA calculations such as "yambo -o c -k alda"? If not, Could you give me some suggestions about where the relevant part in the code and I would like to try to modify the output option in the code.
Thanks!


Shijun Zhao
Peking Unviersity

Dear Shijun,
RPA calculations such as "yambo -o c -k alda" the dyson equation is solved in the G vector (reciprocal space) space, so you do not have access to such information.
Anyway you can solve the same equation (RPA, ALDA) in transition space by: and look into the relevant KS transition forming the excitations as explained in the previous post.

Best,
Daniele