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Data structure of the '.epmatwp' file
Posted: Mon Mar 27, 2017 7:49 pm
by Vince
Dear all,
I am trying to read the content from the unformatted '.epmatwp' file. How can we know the data structure of the '.epmatwp' file from the code? Thank you!
Regards,
Vince
Re: Data structure of the '.epmatwp' file
Posted: Tue Mar 28, 2017 2:35 pm
by sponce
Hello,
The content is:
Code: Select all
DO irq = 1, nrr_q
i = 0
DO imode = 1, nmodes
DO irk = 1, nrr_k
DO jbnd = 1, nbndsub
DO ibnd = 1, nbndsub
i = i + 1
aux (i) = epmatwp(ibnd,jbnd,irk,imode,irq)
ENDDO
ENDDO
ENDDO
ENDDO
CALL davcio ( aux, lrepmatw, iunepmatwp, irq, +1 )
ENDDO
You can find it in ephwann_shuffle.f90
Best,
Samuel
Re: Data structure of the '.epmatwp' file
Posted: Tue Mar 28, 2017 5:58 pm
by Vince
Hi Samuel,
Thank you for your answering. I have two follow-up questions on this:
1. I find that the code you attached is for "etf_mem = true". Is that right? What about "etf_mem = false"?
2. Would you be so kind to let me know how to read the matrix elements in electron wannier - fine bloch phonon grid? (I am assuming it's the epmatwef in ephwann_shuffle.f90 or epmatf in the ephwan2blochp.f90)
Regards,
Vince
Re: Data structure of the '.epmatwp' file
Posted: Wed Mar 29, 2017 9:22 am
by sponce
Hello,
1. It's done in ephbloch2wanp_mem. It should be the same structure but done by part for memory saving.
2. I'm not sure of what you want exactly. epmatf is the electron-phonon matrix element in bloch fine grid space.
Best,
Samuel
Re: Data structure of the '.epmatwp' file
Posted: Wed Mar 29, 2017 3:52 pm
by Vince
Hi Samuel,
About question 2, I mean how can we output the e-ph matrix elements in electron wannier - fine bloch phonon grid? Are they already output to a file by the code, or do we have to write them into a file by ourselves in the code?
Thanks,
Vince
Re: Data structure of the '.epmatwp' file
Posted: Wed Mar 29, 2017 4:04 pm
by sponce
Hello,
I'm not sure of what you mean exactly by "electron wannier - fine bloch phonon grid".
I think it should be the unformatted file ".epmatwe1".
Re: Data structure of the '.epmatwp' file
Posted: Sat Apr 01, 2017 5:13 pm
by Vince
Hi Samuel,
Sorry for the late reply. But ".epmatwe1" is before the Wannier interpolation procedure, right? What is the corresponding file after we interpolate it back into the phonon bloch space?
Thanks,
Vince
Re: Data structure of the '.epmatwp' file
Posted: Mon Apr 03, 2017 1:43 pm
by sponce
Hello,
The .epmatwe1 is an intermediary quantity between coarse reciprocal space and real space. But yet again, I'm not sure of what you are looking for.
The electron-phonon matrix element can be in 3 states:
1) Reciprocal space on the coarse mesh
2) Real space/ Wannier ==> epmatwp
3) Reciprocal space on the fine mesh. ==> not printed to file. In the code it is the epmatf variable.
Which quantity do you want?
Best,
Samuel.