Getting zero value in the O.BGR file from real time simulation with Yambo_rt

[Bramhachari Khamari]

Dear Developers,
I have done the real time simulation by solving the time dependent BSE as implemented in Yambo_rt. By applying a small field and using the DELTA field I could obtained a optical spectrum which looks like the spectrum obtained by solving the GW+BSE method. I want to applied a large intensity field (non-linear case) and see the effect of it in the absorption spectrum. The field related parameter which is used is given as follows.

Code: Select all

% Field1_Freq
 2.230000 | 2.230000 |         eV    # [RT Field1] Frequency
%
Field1_DFreq= 0.000000     eV    # [RT Field1] Frequency step
Field1_Int=100000000.000000       kWLm2 # [RT Field1] Intensity
Field1_Width=0.000000     fs    # [RT Field1] Width
Field1_FWHM=100.000000      fs    # [RT Field1] Full Width at Half Maximum (overwrite width if set)
Field1_kind= "QSSIN"              # [RT Field1] Kind(SIN|RES|ANTIRES|GAUSS|DELTA|QSSIN)
Field1_pol= "linear"               # [RT Field1] Pol(linear|circular)
% Field1_Dir
 0.000000 | 1.000000 | 0.000000 |        # [RT Field1] Versor
%
% Field1_Dir_circ
 0.000000 | 1.000000 | 0.000000 |        # [RT Field1] Versor_circ

Aim is to extract the time dependent change of bands during the time evolution. In order to achieve this, I updated the flag (RTUpdateE # [RT] Update the Energy levels on-the-fly). In the output I could see a new file in the name O.BGR. The output is shown below

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#    Time[fs]           DirGap [meV]       IndGap [meV]       DeltaDirGap [meV]  DeltaIndGap [meV]
#
      0.00000000         0.00000000         0.00000000         0.00000000         0.00000000
     0.100000001         0.00000000         0.00000000         0.00000000         0.00000000
     0.200000003         0.00000000         0.00000000         0.00000000         0.00000000
     0.300000012         0.00000000         0.00000000         0.00000000         0.00000000

Following questions I would like to clarify
i) Is this file(o.BGR) related to band gap renormalization?
ii) At each time step why the gap(direct or indirect) value is not updated and gives zero value for all time start to end. What went wrong?

Regards,

[claudio]

Dear

I'm sorry but the part of o.BGR etc... is not well tested yet and documented,
for this reason we do not provide assistance on this part.

we are working on a new wiki, tests and so on...
Stay tuned on the Yambo webpage

with best regards
Claudio Attaccalite