Optical matrix elements

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

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

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Daniele Varsano
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Re: Optical matrix elements

Post by Daniele Varsano » Tue Dec 17, 2019 3:42 pm

Dear Shudong,
double-check that you extracted the correctly the dipole moments, next if the results are not in agreement in the literature, maybe you want to consider to write to the authors.

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/

Fadil
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Re: Optical matrix elements

Post by Fadil » Mon Dec 13, 2021 2:51 pm

Daniele Varsano wrote: Fri Sep 13, 2019 9:04 am Dear Shudong,
the script reads the dipole databases (ndb.dip_iR_and_P_fragment_*), i.e.
q.<v|r|c>
These are needed both in the IP response function and for the BSE spectra.

Best,
Daniele
Dear all,
The dipole matrix elements obtained from 'ndb.dipoles' are 'i*<v|r|c>' or 'i*q*<v|r|c>'? (where q0 = 10^-5 Bohr)
If the latter, the dipole values should be;
(the extracted value)/(i*q0)

Best
Dr. Fadıl İYİKANAT
ICFO-The Institute of Photonic Sciences
Barcelona-SPAIN

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Daniele Varsano
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Re: Optical matrix elements

Post by Daniele Varsano » Mon Dec 13, 2021 3:42 pm

Dear Fadil,

by default the ndb.dipoles files contains the <iR>, <P> e <v> quantities. No q0 is included there.
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/

Fadil
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Re: Optical matrix elements

Post by Fadil » Tue Dec 14, 2021 10:46 am

Thank you for clarification Daniele.

Best
Dr. Fadıl İYİKANAT
ICFO-The Institute of Photonic Sciences
Barcelona-SPAIN

lyzhao
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Re: Optical matrix elements

Post by lyzhao » Wed Jun 29, 2022 10:27 am

Dear all,
For yambo 4.5.3
I reactivate this post to make sure whether the DIPOLE* module of yambo have calculated the diagonal and intraband optical matrix elements,
such as p_v1v2, p_c1c2, and p_nn, where v =valence, c = conduction, n = any band.

I have noticed the DIP_P(:,iv,iv,ik_mem,i_sp_pol) in line 266 of DIPOLE_transverse.F
but I don't find the DIP_P(:,ic,ic,ik_mem,i_sp_pol)

Best regards.
Youzhao Lan
College of Chemistry and Materials Science,
Zhejiang Normal University,
Jinhua, Zhejiang, China.
HomePage: http://blog.sciencenet.cn/u/lyzhao

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Davide Sangalli
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Re: Optical matrix elements

Post by Davide Sangalli » Tue Jul 05, 2022 10:52 am

Dear Youzhao Lan,
I confirm that yambo, in some cases, computes DIP_P, DIP_v, and if possible also DIP_iR for all nm indexes.

Put

Code: Select all

DipBandsALL
in your input.

Best,
D.
Davide Sangalli, PhD
CNR-ISM, Division of Ultrafast Processes in Materials (FLASHit) and MaX Centre
https://sites.google.com/view/davidesangalli
http://www.max-centre.eu/

lyzhao
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Re: Optical matrix elements

Post by lyzhao » Tue Jul 05, 2022 12:03 pm

Dear Davide Sangalli,
Thanks for your confirmation.

Best regards.
Youzhao Lan
College of Chemistry and Materials Science,
Zhejiang Normal University,
Jinhua, Zhejiang, China.
HomePage: http://blog.sciencenet.cn/u/lyzhao

lyzhao
Posts: 40
Joined: Tue May 31, 2016 8:02 am

Re: Optical matrix elements

Post by lyzhao » Sat Sep 17, 2022 8:13 am

Dear Davide Sangalli,
Can I restrict the range of valence and conduction bands with DipBandsAll?
For example, I have 240 bands. By default, DipBandsAll leads to the dip calculations between 240 bands.
If I only want to calculate the dips between bands in the range of 40-200, is there a keyword for this?
I have tried the following input within an ipa calculation (yambo -o c ), but no effect

Code: Select all

% DipBands
   40 |  200 |                     # [DIP] Bands range for dipoles
%
DipBandsALL               # [DIP] Compute all bands range, not only valence and conduction
Best regards.
Youzhao Lan
Youzhao Lan
College of Chemistry and Materials Science,
Zhejiang Normal University,
Jinhua, Zhejiang, China.
HomePage: http://blog.sciencenet.cn/u/lyzhao

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Davide Sangalli
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Re: Optical matrix elements

Post by Davide Sangalli » Mon Sep 19, 2022 9:44 am

Yeah, you can.

Code: Select all

DipBands

determines the bands range you prefer.
The only requirement is that the first number is smaller or equal than the index of the last occupied band, while the second number is bigger or equal to the index of the first empty band.

Code: Select all

DipBandsAll

just imposes to compute also the CC (conduction-conduction) and VV (valence-valence) matrix elements, and not only the CV (conduction-valence) ones.

Best,
D.
Davide Sangalli, PhD
CNR-ISM, Division of Ultrafast Processes in Materials (FLASHit) and MaX Centre
https://sites.google.com/view/davidesangalli
http://www.max-centre.eu/

Fadil
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Re: Optical matrix elements

Post by Fadil » Tue Sep 27, 2022 9:28 am

Dear all,

For the calculations of dielectric function or EELS with the finite momentum (q =/ 0), how can we extract '<nk| exp(i(q+G)r) | mk-q>' matrix elements as a function of n, m, q, G?

Best
Dr. Fadıl İYİKANAT
ICFO-The Institute of Photonic Sciences
Barcelona-SPAIN

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