Data structure of the '.epmatwp' file

[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

[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

[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

[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

[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

[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".

[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

[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.