Search found 105 matches

by Vahid
Wed Jul 09, 2025 2:35 pm
Forum: Running the code
Topic: IBTE for a metal
Replies: 5
Views: 2320

Re: IBTE for a metal

Dear Shashi, Thank you for this clarification but the change in Fermi energy occurs before IBTE starts (input Fermi level=2.8249eV). Here is the relevant section of the output: ============================================================================================= BTE in the self-energy ...
by Vahid
Fri Jul 04, 2025 3:19 pm
Forum: Running the code
Topic: IBTE for a metal
Replies: 5
Views: 2320

Re: IBTE for a metal

Dear Shashi, I ran an IBTE calculation on the Pb (no SOC) example in the EPW folder. Attached are the input and output EPW files. The Fermi energy is set to 11.7176eV in the input. In the output near the end where the iterative conductivities are printed, the Fermi level is changed by EPW to 11 ...
by Vahid
Thu Jul 03, 2025 7:13 pm
Forum: Running the code
Topic: IBTE for a metal
Replies: 5
Views: 2320

Re: IBTE for a metal

Hi Shashi, Thank you for your input. Using assume_metal = .true. did result in getting the IBTE conductivities for different iterations. I was wondering what should the tag "int_mob" be for IBTE in metals? I set it to false and am getting ~ 54% of the expected conductivity. In addition, the input ...
by Vahid
Sat Jun 28, 2025 7:19 pm
Forum: Running the code
Topic: IBTE for a metal
Replies: 5
Views: 2320

IBTE for a metal

Dear EPW users, I have calculated the el-ph matrix elements for a metal with EPW-5.4.1 and have restarted to calculate the scattering rates and the IBTE. The following tags are set: elph = .true. epbwrite = .false. epbread = .false. epwwrite = .false. epwread = .true. wannierize = .false. scattering ...
by Vahid
Tue Apr 04, 2023 4:52 pm
Forum: Electron-phonon
Topic: Transition probability clarification
Replies: 1
Views: 61641

Transition probability clarification

Dear EPW Community, In transport.f90, the transition probability is defined as ! transition probability ! (2 pi/hbar) * (k+q-point weight) * g2 * ! { [f(E_k+q) + n(w_q)] * delta[E_k - E_k+q + w_q] + ! [1 - f(E_k+q) + n(w_q)] * delta[E_k - E_k+q - w_q] } The first term is absorption (+w_q) and the ...
by Vahid
Sat Mar 18, 2023 7:27 pm
Forum: General discussion
Topic: Emission vs. absorption coupling constant mismatch in Si
Replies: 3
Views: 21639

Re: Emission vs. absorption coupling constant mismatch in Si

Dear H. Lee, I changed the q-grid to 12x12x12, matching the k-grid. The electron and phonon dispersions from EPW match those of QE. The PSP is norm-conserving. After some digging into the code, I believe the mismatch between emission and absorption coupling constant comes from the phase factor exp ...
by Vahid
Sat Mar 04, 2023 11:57 am
Forum: General discussion
Topic: Emission vs. absorption coupling constant mismatch in Si
Replies: 3
Views: 21639

Re: Emission vs. absorption coupling constant mismatch in Si

Dear H. Lee, I am using a norm-conserving PSP. The coarse k-grid is 12x12x12 and q-grid is 6x6x6. These give converged EPW band structure and phonon dispersion relative to QE counterparts. I was expecting some differences in g2 but not a factor of 100. I will dig further into the code. There might ...
by Vahid
Thu Mar 02, 2023 5:22 pm
Forum: General discussion
Topic: Emission vs. absorption coupling constant mismatch in Si
Replies: 3
Views: 21639

Emission vs. absorption coupling constant mismatch in Si

Dear EPW community, I am studying the following emission/absorption pair in silicon: I start with a single k-point (0.0 0.3 0.3) and a single q-point (0.0 0.1 0.1). My kq-point is (0.0 0.4 0.4). I print g2 from transport.f90. For mode #6, g2=9.51E-9. Then I use k-point (0.0 0.4 0.4) and q-point (0.0 ...
by Vahid
Mon Nov 07, 2022 7:07 pm
Forum: Theory
Topic: EPW velocity Definition between QE-6.0 and QE-7.0
Replies: 3
Views: 56640

Re: EPW velocity Definition between QE-6.0 and QE-7.0

Dear H. Lee,

Thank you for your response. Upto qe-6.7MAX, the factor 2 is included in the velocity expression. Only 6.8 and 7.0 have removed the 2.

Thanks,
Vahid
by Vahid
Mon Nov 07, 2022 2:58 pm
Forum: Theory
Topic: EPW velocity Definition between QE-6.0 and QE-7.0
Replies: 3
Views: 56640

Re: EPW velocity Definition between QE-6.0 and QE-7.0

Since there has been no response, is it safe to assume that one of those versions is incorrect?

Thanks,
Vahid