Yambo Community Forum

Dear professor Prof. Maurizia Palummo,
I have some questions regarding the calculation of the lifetime of excitons. I would like to do the calculation using the following procedure: Using the formula from the following article https://pubs.acs.org/doi/10.1021/nl503799t . Here I would like to start from your following input file https://github.com/mpalummo/DFT-2D then generate the o-exc_qpt1_E_sorted file to calculate mu_S^2 by the relation: mu_S^2 = Strength*Maximum Residual Value. My objectives are to define a method for doing the calculation and to ensure that this method works I would like to test it on a solved case, i.e. yours (in order to find your respective values)

I look forward to your response.
THANKS
SAM
PhD student at University of Lome/Togo

Dear Sam,

what is your question exactly?

Best,
Daniele

Dear Daniele,
Thank you for answering me.

My question is if it is possible to do this to calculate the lifetime of the excitons. That is to say doing DFT calculations (scf, nscf, phonon) of the materials then at the level of the yambo calculations solve the BSE, then sort the exictons with ypp_ph -e s in order to generate the file o-T0_BSE.exc_qpt1_E_sortede which allows me to calculate mu_s^2 = Force * (Maximum residual value).


my second question is to know what difference there is between the lifetime of the excitons calculated in the tutorials on luminescence with the yambo command: yambo_ph -exph l and that calculated in the article.
Thanks

SAM
PhD student at University of Lome/Togo

Dear Sam,
the difference between the two calculations is that in the tutorial it is explained how to calculate the lifetime of a phonon-mediated luminescence process, while the calculation in the paper you mentioned is a calculation for a radiative direct process. About the details of the latter, Maurizia Palummo will answer you in the next few days.

Best,
Daniele

Dear Daniele,
thank you for responding so soon.
I would like to submit a complaint regarding the phonon-assisted luminescence tutorials. Is it possible to leave us a bash script to automate the calculation until the difference calculation is finished. this will allow me to follow the script and understand better. I'm having a really hard time handling giving them right after the 12 input file is generated.
THANKS
SAM
PhD student at University of Lomé

Dear Sam,

please note that the phonon assisted luminescence is an experimental feature as clearly stated in the tutorial as at moment there are issues on the phase mismatch. A new tutorial will be provided in the next future when the feature will be released.

Best,
Daniele