questions about SHG of InSe

Can't find a suitable forum for your query? Post it here.

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

Post Reply
Dean
Posts: 16
Joined: Thu Oct 10, 2019 7:03 am

questions about SHG of InSe

Post by Dean » Tue Nov 26, 2019 2:19 am

Dear developers,
I am reading the paper "Second-harmonic generation in single-layer monochalcogenides: A response from first-principles real-time simulations" (PHYSICAL REVIEW MATERIALS 3, 074003 (2019)). I am very interested in the calculations of SHG of 2D materials and wnat to learn it.
So, I did some calculations of InSe monolayer, but something goes worng. Can you give me some help?
Here is my yambo_nl input file:
FFTGvecs= 21125 RL # [FFT] Plane-waves
% NLBands
16 |23 | # [NL] Bands
%
NLstep= 0.02 fs # [NL] Real Time step length
NLtime=75.000000 fs # [NL] Simulation Time
NLintegrator= "INVINT" # [NL] Integrator ("EULEREXP/RK2/RK4/RK2EXP/HEUN/INVINT/CRANKNIC")
NLCorrelation= "IPA" # [NL] Correlation ("IPA/HARTREE/TDDFT/LRC/LRW/JGM/SEX")
NLLrcAlpha= 0.000000 # [NL] Long Range Correction
% NLEnRange
0.300000 | 5.000000 | eV # [NL] Energy range
%
NLEnSteps= 80 # [NL] Energy steps
NLDamping= 0.100000 eV # [NL] Damping
% ExtF_Dir
1.000000 | 0.000000 | 0.000000 | # [NL ExtF] Versor
%
ExtF_FrStep= 0.000000 eV # [NL ExtF] Frequency step
ExtF_Int= 500. kWLm2 # [NL ExtF] Intensity
ExtF_Damp= 2.000000 fs # [NL ExtF] FWHM
ExtF_kind= "SOFTSIN" # [NL ExtF] Kind(SIN|SOFTSIN|RES|ANTIRES|GAUSS|DELTA|QSSIN)
ExtF_Tstart= 0.0100 fs # [NL ExtF] Initial Time
GfnQPdb= "none" # [EXTQP G] Database
GfnQP_N= 1 # [EXTQP G] Interpolation neighbours
% GfnQP_E
1.330000 | 1.000000 | 1.000000 | # [EXTQP G] E parameters (c/v) eV|adim|adim
%

And ypp_nl input file:
nonlinear # [R] NonLinear Optics Post-Processing
Xorder=4 # Max order of the response functions
% TimeRange
34.00 | 75.00 | fs # Time-window where processing is done
%
ETStpsRt=200 # Total Energy steps
% EnRngeRt
0.30 | 5.00 | eV # Energy range
%
DampMode= "NONE" # Damping type ( NONE | LORENTZIAN | GAUSSIAN )
DampFactor= 0.100000 eV # Damping parameter

My question is : 1. Are the input files right?
2. How to deal with the output file "o-2D.YPP-X_probe_order_2" in order to get the SHG coefficients of InSe?
Thanks in advance.
Dr. Yimin Ding
Soochow University, China.

User avatar
claudio
Posts: 228
Joined: Tue Mar 31, 2009 11:33 pm
Contact:

Re: questions about SHG of InSe

Post by claudio » Tue Nov 26, 2019 11:46 am

Dear Dr. Yimin Ding

your input files seem correct to me. I will only change the NLstep= 0.01 fs

what problem did he have?

Regarding the file o-2D.YPP-X_probe_order_2 it contains the X2 coefficients. The X^2_{xxy},
because you put the incoming field in x and measure the non-linear response in y.


In particular, the ones plotted in the paper are the 5 and 6 columns.
Remember that you have to rescale them:
1) fist from m/V to the CGS system, divide for 2.38721e-09
2) you have to rescale for the box size respect to the width of the material, for example,
if you have simulation box 35 a.u. high and your material width is 15.042219756 a.u.
you rescale for 35.0/15.042219756

let me know if it is clear
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
Freely download scientific books from: http://www.freescience.info

Dean
Posts: 16
Joined: Thu Oct 10, 2019 7:03 am

Re: questions about SHG of InSe

Post by Dean » Wed Nov 27, 2019 3:11 am

Dear Dr. Claudio,
Thanks for your reply.
My plot of X2 coefficients shows that the peak shifts to higher energy range. See the attachments please.
Look forward to your reply.
You do not have the required permissions to view the files attached to this post.
Dr. Yimin Ding
Soochow University, China.

User avatar
claudio
Posts: 228
Joined: Tue Mar 31, 2009 11:33 pm
Contact:

Re: questions about SHG of InSe

Post by claudio » Wed Nov 27, 2019 9:32 am

Dear Dr. Yimin Ding

I agree with you, but in your input, you introduced a shift of 1.33 eV

% GfnQP_E
1.330000 | 1.000000 | 1.000000 | # [EXTQP G] E parameters (c/v) eV|adim|adim
%

while in the IPA plot of my paper this is not present.
Try to use 0 shift and a mearing of 0.2 eV, you will get the same plot in IPA.

let me know
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
Freely download scientific books from: http://www.freescience.info

Dean
Posts: 16
Joined: Thu Oct 10, 2019 7:03 am

Re: questions about SHG of InSe

Post by Dean » Thu Nov 28, 2019 2:18 am

Dear Dr. Claudio,
Thanks for your reply.
I still have the following questions:
1.Why the Xorder in ypp.in is set as 4 not 2?
2.The smearing you said is "NLDamping= 0.100000 eV" in yambo.in or "DampFactor= 0.100000 eV" in ypp.in?
3. I initially want to repeat the results of G0W0+BSE. How to do that?
4. The Tutorials of non-linear calculations will be put on the new official website of yambo or wiki website?
Look forward to your reply.
Dr. Yimin Ding
Soochow University, China.

User avatar
claudio
Posts: 228
Joined: Tue Mar 31, 2009 11:33 pm
Contact:

Re: questions about SHG of InSe

Post by claudio » Thu Nov 28, 2019 9:17 am

Dear Dr. Yimin Ding

here the reply to your questions:

>1.Why the Xorder in ypp.in is set as 4 not 2?

the non-linear response is extract by fitting the time dependent polarization, we think it is better to use more coefficient
for the fit up to 4 I will say. See Eq. 26, 27 and 28 of https://arxiv.org/pdf/1309.4012.pdf.
You can test if putting only 2 gives you the same result.

>2.The smearing you said is "NLDamping= 0.100000 eV" in yambo.in or "DampFactor= 0.100000 eV" in ypp.in?

The DampFactor in ypp.in is valid only in linear optics, and actived if you select a DampMode different from "NONE"
I will add a comment in the tutorial on this point.

>3. I initially want to repeat the results of G0W0+BSE. How to do that?

Follow the step of the turorial on BSE
http://www.attaccalite.com/lumen/real_time_bse.html
and calculate the non-linear response.

>4. The Tutorials of non-linear calculations will be put on the new official website of yambo or wiki website?

yes, soon.

best regards
Claudio Attaccalite
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
Freely download scientific books from: http://www.freescience.info

Dean
Posts: 16
Joined: Thu Oct 10, 2019 7:03 am

Re: questions about SHG of InSe

Post by Dean » Sun Dec 01, 2019 6:41 am

Dear Dr. Claudio,
Thanks very much.
Dr. Yimin Ding
Soochow University, China.

Post Reply