Xd damping range

You can find here problems arising when using old releases of Yambo (< 5.0). Issues as parallelization strategy, performance issues and other technical aspects.

Moderators: Davide Sangalli, andrea.ferretti, myrta gruning, andrea marini, Daniele Varsano, Conor Hogan

User avatar
claudio
Posts: 528
Joined: Tue Mar 31, 2009 11:33 pm
Location: Marseille
Contact:

Re: Xd damping range

Post by claudio » Wed Feb 19, 2020 1:34 pm

Dear Haseeb Ahmad

you should use an input like

% DmRngeXd
0.80000 | 0.10000 | eV # [Xd] Damping range
%

where 0.8 is the maximum value of the damping at the beginning of your spectra,
and 0.1 the minimum at the end of your spectra (higher energies)

best
Claudio
Claudio Attaccalite
[CNRS/ Aix-Marseille Université/ CINaM laborarory / TSN department
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09
web site: http://www.attaccalite.com

haseebphysics1
Posts: 169
Joined: Sat Aug 17, 2019 2:48 pm

Re: Xd damping range

Post by haseebphysics1 » Wed Feb 19, 2020 7:18 pm

Thanks, dear claudio.
Haseeb Ahmad
MS - Physics,
LUMS - Pakistan

haseebphysics1
Posts: 169
Joined: Sat Aug 17, 2019 2:48 pm

Re: Xd damping range

Post by haseebphysics1 » Mon Mar 02, 2020 3:17 pm

Deal Yamboers,

I want to ask a simple question, when I am applying a large non-uniform damping in the optical absorption spectra than the peak position also changes slightly! Since I am applying the LRC alpha value in TDDFT and fitting the result againt experimental result, so changing the spectrum with anything other than alpha value is not satisfactory! Moreover, I am also doing the same calculation with Spin-orbit coupling as well, so if peak position is the dependent upon the damping range then I will not be able to compare the results!

So, is it good idea to make damping range fixed for all the future theoretical calculations? No matter if it fits with experimental curve or not?

Thanks,
Haseeb Ahmad
MS - Physics,
LUMS - Pakistan

User avatar
Daniele Varsano
Posts: 4209
Joined: Tue Mar 17, 2009 2:23 pm
Contact:

Re: Xd damping range

Post by Daniele Varsano » Mon Mar 02, 2020 3:32 pm

Dear Haseeb,
the peak position also changes slightly!
The damping just broad your peaks according to a Lorentzian shape, if the peak position changes I presume you are just summing up weights of neighbouring excitations.
So, is it good idea to make damping range fixed for all the future theoretical calculations? No matter if it fits with experimental curve or not?
I would say yes, it is a good idea to keep it fixed to a reasonable value, otherwise, you risk to mask the effects of different approximations.
Best,
Daniele
Dr. Daniele Varsano
S3-CNR Institute of Nanoscience and MaX Center, Italy
MaX - Materials design at the Exascale
http://www.nano.cnr.it
http://www.max-centre.eu/

Locked