Search found 14 matches

by tswang
Mon Jul 17, 2017 1:29 am
Forum: General discussion
Topic: Electron linewidth of symmetrically degenerated kpoints
Replies: 2
Views: 3875

Re: Electron linewidth of symmetrically degenerated kpoints

Dear Samuel,

Thank you for your reply! I will check the convergence.

Best
Tianshi
by tswang
Tue Jul 11, 2017 12:26 am
Forum: General discussion
Topic: Electron linewidth of symmetrically degenerated kpoints
Replies: 2
Views: 3875

Electron linewidth of symmetrically degenerated kpoints

Dear EPW users, I find that the electron linewidth, comprising of both long-range and short-range terms, for equivalent k-points are not exactly the same. Sometimes, the difference can reach 50% in my calculation of a polar material- zinc blende GaAs. For example, the linewidth at (0, 0.02, 0) in cr...
by tswang
Tue May 16, 2017 7:17 pm
Forum: General discussion
Topic: Electron self-energy in polar material
Replies: 4
Views: 4876

Re: Electron self-energy in polar material

Dear Dr. Ponce,

Got you. Thanks a lot!

Tianshi
by tswang
Tue May 16, 2017 2:34 pm
Forum: General discussion
Topic: Electron self-energy in polar material
Replies: 4
Views: 4876

Re: Electron self-energy in polar material

Hi Dr. Ponce, Thank you for your prompt reply. I appreciate it. You remark in the code that the short-range term still contains a linear long-range part. Does it mean that the short-range term in polar materials has the form as |g S ^2+2g L g S | where g S is the matrix elements in non-polar materia...
by tswang
Mon May 15, 2017 9:03 pm
Forum: General discussion
Topic: Electron self-energy in polar material
Replies: 4
Views: 4876

Electron self-energy in polar material

Dear EPW users, I have a question about computing electron self-energy in polar materials. As described in the code, computing the long-range and short-range terms separately may improve convergence. To get the self-energy for each k-point, can I simply sum that from long-range and short-range terms...
by tswang
Sat Mar 11, 2017 5:02 pm
Forum: General discussion
Topic: Reasonable values of degaussw
Replies: 3
Views: 4657

Re: Reasonable values of degaussw and

Dear Dr. Margine, Thank you very much for your prompt reply. So a smearing (degaussw) less than 1 meV is usually not needed. The degaussw and k-mesh size are correlated during the convergence test. Therefore, is it ok that I set degaussw as 1 meV and only test the size of k and q meshes? Do you have...
by tswang
Sat Mar 11, 2017 2:06 pm
Forum: General discussion
Topic: Reasonable values of degaussw
Replies: 3
Views: 4657

Reasonable values of degaussw

Hi all, I am working on the thermal conductivity from the EPI for doped materials like the example of B-doped diamond. I would like to know the reasonable minimum degaussw. That's because I probably need a very small value since the doping move the Fermi level below VBM by only 3-100 meV. On the oth...
by tswang
Fri Mar 10, 2017 8:27 pm
Forum: General discussion
Topic: Calculate electron mobility in doped materials
Replies: 1
Views: 3075

Calculate electron mobility in doped materials

Dear developer, I am trying to calculate electron mobility in doped materials to get a function of electron mobility with respect to carrier concentration from electron/phonon interaction. I can see two possible options: 1. Change the pseudopotential by increasing/decreasing the valence electron num...
by tswang
Mon Oct 31, 2016 2:33 pm
Forum: Running the code
Topic: B doped diamond example
Replies: 3
Views: 4142

Re: B doped diamond example

Hi Samuel, Thank you for your reply! It is very helpful to me. I chose (0 for dis_froz_max, 10 for dis_win_max) for p-type and (10, 16) for n-type based on my understanding. The interpolated band structure doesn't have notable change. Do you think it is fine? This material is 3C-SiC. The band gap is...
by tswang
Fri Oct 28, 2016 1:28 pm
Forum: Running the code
Topic: B doped diamond example
Replies: 3
Views: 4142

B doped diamond example

Dear users, In the diamond example, the chosen dis_froz_max and dis_win_max are 7 and 15 eV, respectively. Why do we choose the values? Why don't we choose 15eV for dis_froz_max since we are interested in the four valence band? If my nbnd=6, should I use dis_win_max=20? What about n-type diamond? Sh...