Oscillator strength

Deals with issues related to computation of optical spectra in reciprocal space: RPA, TDDFT, local field effects.

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xtbu
Posts: 16
Joined: Sat Jul 20, 2019 4:15 am

Oscillator strength

Post by xtbu » Thu Apr 02, 2020 12:27 pm

Dear all,
I want to get the oscillator strength exactly expression. Is it as I=(|Ac,v<c|D|v>|^2)/E?Or maybe something is missing ?
Thanks!

Xiangtian
X. T. Bu
Beijing Institute of Technology, China

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Daniele Varsano
Posts: 4231
Joined: Tue Mar 17, 2009 2:23 pm
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Re: Oscillator strength

Post by Daniele Varsano » Thu Apr 02, 2020 12:46 pm

Dear Xiangtian,

you can access the oscillator strenght by using ypp (sorting and report).
IN the output file you will have the excitation energy and the intensity defined as |Ac,v<c|D|v>|^2
Note that by default the values are normalized to the higher Residual value (higher intensity). The value of tme maximum is report in the output
as:

Code: Select all

Maximum Residual Value
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/

emarinho
Posts: 3
Joined: Mon Jan 30, 2023 2:08 pm

Re: Oscillator strength

Post by emarinho » Sat Jul 27, 2024 2:04 am

Dear all,

Does the Maximum Residual Value indeed represent the maximum value of the oscillator strength? Is this a dimensionless quantity or does it have units?

Best regards,
Enesio Marinho
Dr. Enesio Marinho Jr
Department of Physics and Chemistry
São Paulo State University (UNESP), Ilha Solteira, São Paulo, Brazil

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Daniele Varsano
Posts: 4231
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Re: Oscillator strength

Post by Daniele Varsano » Mon Jul 29, 2024 8:48 am

Dear Enesio,

the Max residual is defined in:
ypp/excitons/excitons_sort_and_report.F

If you note that the BS_R has the dimension of a length (dipole), the reported strength should be adimensional.

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/

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