Problem with calculating polaron equation

[Qiaolin]

Dear developers,

I am trying to calculate the formation energy of hole polarons in 3C-SiC with coarse k/q grids (e.g, nkf1=nkf2=nqf3=6x6x6). When setting `fermi_energy` close to Evbm, we get a formation energy of about -14.7842720 eV, but without setting `fermi_energy`, we get a value of -0.0011676 eV. I don't know which is correct.

Best,
Qiaolin

[zhenbang]

Hi Qiaolin,

The polaron module does not support reading fermi energy from input, and the current implementation will give some silent bugs if you set fermi_energy in the input file. So you should trust the value that you got without setting fermi_energy. This bug will be fixed a near future release.

Best,
Zhenbang

[Qiaolin]

Dear Zhenbang,

Thanks for your reply.

Without setting `fermi_energy`, I have another question . If I want to investigate the formation of hole polarons, I wander if `num_wann` should contain only the number of valence bands. I noticed that the obtained Wannier functions correspond only to the valence bands, or to both the valence and conduction bands, and they give different results.

Best,
Qiaolin