sheriftawfikabbas / pyphotonics Goto Github PK

Dear Altruists

Thank you very much for developing such a nice tool to calculate photoluminescence (PL). Sir, I am trying to calculate the PL spectrum of GaN and followed each ground state, excited state, and vibrational calculation. Then, when I ran the python code to calculate the PL-spectrum, I found no peak in the generated 'I.png' file. I modified the values in the A, I = p.PL(2, 2, 1.95) line arbitrarily but could not understand the proper meaning of these values in the () bracket.

Can you please help me with this issue of setting proper values in the () bracket? Thank you very much for your kind consideration.

Best regards
Arindam Sannyal

https://github.com/sheriftawfikabbas/pyphotonics/blob/720584f6505fa7d07411b591bc3906e71b28a987/pyphotonics/photoluminescence.py#L198C50-L198C50

I want to know why you have multiplied (1.0545718e-34 * 6.582119514e-16) in the above line. However, both represent h_bar in different units.

Reduced Plank Constant = 1.054571817...×10−34 J⋅s (=6.582119569...×10−16 eV⋅s)

While testing the code, I got unreasonable large Delta_R, Delta_Q, and HuangRhyes factor for the NV center in diamond.
This is because I used a different defect supercell. In this cell, the defect is placed at the corner instead of the center of the supercell, as in the example in the repo. To verify that this change was responsible for the difference, I shifted the defect in the example to the corner and could recreate the unreasonable large values.

With the attached infiles
shifted_NV.tar.gz
I got the following values:
Delta_R= 7.145141461466035
Delta_Q= 24.76297908689863
HuangRhyes= 8760.021847986585
These are so large that I get an overflow error, and the calculation stops.

These values should be the same as in the example since a translation should not affect the result.
The reason is that atoms move across the cell boundary between the ground and excited state and end up at different corners of the supercell. Therefore, when Delta_R is calculated, periodic boundary conditions are not handled.

I verified this with a minimal example using one atom in a large box 10 Å.
minimal_example.tar.gz
I moved the atom over the cell boundary between the ground and excited state, corresponding to a movement of 2 Å.
However, without periodic boundary conditions, the distance is 8 Å which is the result PyPhotonics gives:
Delta_R= 8.0
Delta_Q= 29.940741473784513
HuangRhyes= 0.0

HI

I calculated S(omega) and PL for my structure but how can i get raw data

Regards

Khaled

I am really interested in calculating Huang-Rhys factor, however, the code does not have interface with QUANTUM ESPRESSO

Dear Sir

Thank you very much for developing such a nice code for photonic properties. Sir, I would like to know that is it possible to calculate Auger carrier lifetime by PyPhotonics as it is mentioned that soon PyPhotonics will be able to calculate the carrier lifetimes for defects.

Thank you very much for your time.

Best regards
Arindam Sannyal