the drag effect of different concentrations.

[cumtra]

Dear Nakib,
Thank you for this very useful code.
I don't know how to set ‘dopingtype’, ‘numconc, conclist‘, ’‘numT’, and ‘Tlist’ under Namelist electrons When setting the runlevel = 0.

Thanks！

[nakib]

Dear cumtra,

You can add something like the following in the electrons namelist when doing a runlevel = 0 calculation for an n-doped system:

dopingtype = "n"
numconc = 5
conclist = 1e16 1e17 1e18 1e19 1e20
numT = 8
Tlist = 50.0 100.0 150.0 200.0 150.0 300.0 350.0 400.0

This will produce a file called chempot-T_table.txt that will contain the chemical potentials corresponding to the listed concentrations for the listed temperature points.

For runlevel 1, Zn and/or Zp has to be set if you include electron-charged impurity scattering.

All of the above quantities are explained here: https://github.com/nakib/elphbolt#electrons.

Best,
Nakib

[cumtra]

Thank you very much for your answer！

Best

[cumtra]

Dear Nakib,
I want to know whether elphbolt can calculate the mean free path(MFP) of phonon. If so, how to set the parameters to calculate the MFP.

Thanks!
Best

[nakib]

Dear cumtra,

This is currently available only for the dragless full phonon BTE and through the post-processing runlevel. I have not yet implemented it for the dragful case. If you are comfortable with coding, you can hack it together pretty easily just by following what I did in the subroutine postproc in the file src/bte.f90. (Search for the term "mean-free" to jump to the relevant sections.)

For the dragless phonon BTE case, after you are done doing the phonon BTE calculation, you need to re-run elphbolt with the following added to the numerics namelist. Play around with the numbers, as necessary for your system.

&numerics
...

!Spectral coefficients calculation:
        runlevel = 2 !post-processing step

        ph_en_num = 200
        ph_en_min = 0.0
        ph_en_max = 0.100
        ph_mfp_npts = 500
/ 

The necessary files for the MFP will be generated in your output/T* directory. These are:

1. nodrag_iterated_ph_mfps_sampling
2. nodrag_iterated_ph_mfps_ibz (branch resolved)
3. nodrag_iterated_ph_kappa_mfp_cumulative_* (3x3 tensor for each branch [integer number in filename] and branch-summed [total in filename])

You can use 1 and 3 to generate a plot like

and 2 and the ibz phonon energies to generate a plot like

The above plots are from https://arxiv.org/pdf/2306.16980.pdf.

Best,
Nakib

[nakib]

p.s. If you are comfortable with the Julia language, you can try to write the MFP calculator in that. I plan to move all the post-processing stuff to Julia. Any community contribution will be strongly appreciated.

Best,
Nakib