Modeling of the SiC

[mishchenka]

Dear all,

In order to understand why I could not perform earlier simulation for modified graphene with epw.x program, I tried to perform an example simulation on your site for SiC material using QE-6.7 software package and EPW program at sequential run. The simulation using the input files SiC.scf.in, SiC.nscf.in, SiC.ph.in was successful. I used the following commands:

/home/user/qe-6.7/bin/pw.x </home/user/qe-6.7/bin/SiC.scf.in> /home/user/qe-6.7/bin/SiC.scf.out
/home/user/qe-6.7/bin/pw.x </home/user/qe-6.7/bin/SiC.nscf.in> /home/user/qe-6.7/bin/SiC.nscf.out
/home/user/qe-6.7/bin/ph.x </home/user/qe-6.7/bin/SiC.ph.in> /home/user/qe-6.7/bin/SiC.ph.out

I copied the sic.save and _ph0 folders from the QE-6.7 program from /home/user/qe-6.7/bin to /home/user/qe-6.7/EPW/bin, where the epw.x program is located. I created an additional folder SiC to store the input and output files.

But when I execute the command
/home/user/qe-6.7/EPW/bin/epw.x </home/user/qe-6.7/EPW/SiC/SiC.epw.in> /home/user/qe-6.7/EPW/SiC/SiC.epw.out

I received an answer:

Error in routine elphon_shuffle_wrap (1):
Problem with modes file
stopping.........

In the application I am sending the input and output files for the epw.x program.

Best regards,
Mishchenka Valery.

[hpaudya1]

Hi Mishchenka,

You missed a step to collect required files from the phonon calculation (*.dyn, *.dvscf, and patterns*) in a specific directory with required file names, and this directory should be defined in dvscf_dir = ' ' (https://docs.epw-code.org/doc/Inputs.html#dvscf-dir) in epw input file. This can be done using a small python script available in q-e/EPW/bin/pp.py

Please have a look at this example
https://docs.epw-code.org/doc/SiC.html

Best,
Hari

[hlee]

Dear Mishchenka Valery:

I would like to add a small thing to Hari's answer:
When running the python script of pp.py in the directory of /home/user/qe-6.7/EPW/bin/ , please use the python version 3.X.

Sincerely,

H. Lee

[mishchenka]

Dear Hari and H. Lee,

Thank you for your response to the letter of June 12, 2021. According to your instructions I tried to copy the files using the program pp.py. However, I noticed that there are two versions of the pp.py program. The first version is in the examples folder for the SiC material. The second version of this program is contained in the /home/user/qe-6.7/EPW/bin folder.
When using the first version of the program using the command:

/home/user/qe-6.7/EPW/examples/sic/phonons/pp.py

I got an answer as shown in screenshot N1-a.

When using the second version of the program using the command:

/home/user/qe-6.7/EPW/bin/pp.py

I got the answer as shown in screenshot N2-a.

I have two versions of the Python program installed on my computer as shown in screenshoot N3.


Would you be kind enough to tell me which version of pp.py and how I should run programm without errors.

Best regards,
Mishchenka Valery.

[hlee]

Dear Mishchenka Valery:

I would suggest you to issue the following:
$python3 /home/user/qe-6.7/EPW/bin/pp.py

The script of pp.py in /home/user/qe-6.7/EPW/bin should be run by python3 .

Sincerely,

H. Lee

[mishchenka]

Dear H. Lee,

Thank you for your response to the letter of June 16, 2021. According to your instructions I executed the command suggested in your letter. The program prompted me to insert the prefix to continue as shown in the screen shot attached to this letter. However, when I entered the prefix, i.e. the path where my files from the simulation of qe-6.7 are located:

/home/user/qe-6.7/bin

the error shown in the screenshot in the appendix occurred.

Please be kind enough to point me to the error that occurs at this stage of the simulation. My .dyn files are located at /home/user/qe-6.7/bin and there are two folders from the previous stages of the simulation when running scf.in and ph.in, located at

/home/user/qe-6.7/bin/sic.save
/home/user/qe-6.7/bin/_ph0


Best regards,
Mishchenka Valery.

[hlee]

Dear Mishchenka Valery:

However, when I entered the prefix, i.e. the path where my files from the simulation of qe-6.7 are located:

/home/user/qe-6.7/bin

You need to enter the prefix only, that is, sic .

In any case, sic.dyn* files should be in your working directory.

Sincerely,

H. Lee

[mishchenka]

Dear H. Lee,

Thank you for your response to the letter of June 17, 2021.

According to your instructions I executed the command suggested in your letter.
However, when I entered the sic there was an error as shown in the screenshot n9 in the appendix.
My files _ph0/sic.q2_/sic.wfc ( and the other 15 files) are located at /home/user/qe-6.7/EPW/bin/_ph0. The location of these files is shown in the screen shots n6-n7 in the appendix. Thus sic.wfc files are located in their sic.q_2 (sic.q_3 and so on) folders.

Would you be kind enough to point me to an error that occurs at this stage of the simulation.

Best regards,
Mishchenka Valery.

[hlee]

Dear Mishchenka Valery:

Something messed up.
After the successful run, there should be the "save" directory which contains all necessary files for EPW calculation.

/home/user/qe-6.7/bin/pw.x </home/user/qe-6.7/bin/SiC.scf.in> /home/user/qe-6.7/bin/SiC.scf.out
/home/user/qe-6.7/bin/pw.x </home/user/qe-6.7/bin/SiC.nscf.in> /home/user/qe-6.7/bin/SiC.nscf.out
/home/user/qe-6.7/bin/ph.x </home/user/qe-6.7/bin/SiC.ph.in> /home/user/qe-6.7/bin/SiC.ph.out

This is not a correct procedure.

Please follow the instructions in https://docs.epw-code.org/doc/SiC.html .

Sincerely,

H. Lee

[mishchenka]

Dear H. Lee,

Thank you for your response to the letter of June 18, 2021. Following your instructions I ran the command sequence shown in screenshot n10 in the appendix. As you see (screenshot n10), the sic command went through without problems. But when I running the program epw.x with the input file sic.epw.in an error Stop 1 occurred, the details of which are shown below and in the file sic.epw.out.

Error in routine check_is_xml_file (1):
Expected a file named either '/home/user/qe-6.7/EPW/bin/_ph0/sic.dyn_q1

Please be kind enough to point me to the error that occurs at this stage of the simulation.

Best regards,
Mishchenka Valery.