convergence issue in BTE mobility calculation

[Sumit]

Dear Developers,

I am trying to calculate the electron and hole mobility in a 2D system. Doing the iterative_bte calculation, I found calculations are not converged even after 1000 iterations and show negative value of mobility tensor like:


-0.116797E+04 -0.266909E+04 0.189661E-12
-0.266292E+04 0.192852E+04 0.109511E-12
0.190097E-12 0.109757E-12 0.261935E-27

0.904978E+02 Max error

1.Can you please suggest a way to converge the calculation with or without a magnetic field?
2.Is there any role of fsthick on the convergence of mobility calculation? I find on the website that this value indicates the fermi surface thickness to consider self-energy calculation. But still, I am unable to understand how to take this value for a semiconductor so that convergence can be achieved.
3. The negative mobility number does not seem meaningful.

Kindly comment on the questions.

Thank You

Regards
Sumit Kukreti
Ph.D. scholar, Physics
IIT Jodhpur INDIA

[Sumit]

Dear Developers,

If you have any suggestions regarding the asked queries. Please tell me.
Some queries are:
how to pick fsthick value
how to make sure convergence with BTE

Thank You

Regards
Sumit Kukreti