Search found 172 matches

by roxana
Tue Jun 27, 2023 9:59 pm
Forum: General discussion
Topic: Different Tc obtained in EPW and lambda.x calculation
Replies: 1
Views: 20796

Re: Different Tc obtained in EPW and lambda.x calculation

Hi,

You need to converge lambda with both k and q meshes. This is not very easily done in QE since the k and q meshes used are in general pretty coarse.

Best,
Roxana
by roxana
Tue Jun 27, 2023 9:50 pm
Forum: Running the code
Topic: lambda___( 1 )=***************
Replies: 1
Views: 2230

Re: lambda___( 1 )=***************

Hi, The *** means that not enough digits are printed. Currently, the format in selfen.f90 if f15.6. You can change this to more digits. However, the values that you are getting appear too large. selfen.f90: 104 FORMAT(5x, 'lambda_tr( ',i3,' )=', f15.6, ' gamma_tr=', f15.6, ' meV', ' omega=', f12.4, ...
by roxana
Tue Jun 27, 2023 2:03 pm
Forum: Running the code
Topic: forrtl: severe (174): SIGSEGV, segmentation fault occurred
Replies: 6
Views: 13808

Re: forrtl: severe (174): SIGSEGV, segmentation fault occurred

Hi,

Can you please also use the latest released version 5.7?

Best,
Roxana
by roxana
Tue Jun 27, 2023 1:24 pm
Forum: General discussion
Topic: dielectric tensors in phonon calculation using the QE
Replies: 1
Views: 20928

Re: dielectric tensors in phonon calculation using the QE

Hi,

Please post questions about QE on the QE forum.

Best,
Roxana
by roxana
Wed Jun 07, 2023 5:22 pm
Forum: Running the code
Topic: Negative value of superconducting gap
Replies: 13
Views: 38418

Re: Negative value of superconducting gap

Hi,

Larger the \mu* value stronger the Coulomb effect and therefore smaller the Tc and gap.

Best,
Roxana
by roxana
Wed Jun 07, 2023 4:01 pm
Forum: Running the code
Topic: EPW code v5.7 polaron calculation
Replies: 1
Views: 3573

Re: EPW code v5.7 polaron calculation

Hi,

You can find a tutorial with input file under the "Hands-on tutorial: Polarons" at the link below:

https://epw2023.dryfta.com/74-schedule

Best,
Roxana
by roxana
Wed Jun 07, 2023 3:55 pm
Forum: Running the code
Topic: Negative value of superconducting gap
Replies: 13
Views: 38418

Re: Negative value of superconducting gap

Hi Shubham,

I would recommend running calculations with different \mu* values starting from \mu*=0 and see at which value the lower gap becomes negative.

Best,
Roxana
by roxana
Wed Jun 07, 2023 3:42 pm
Forum: Running the code
Topic: Printing complex electron-phonon matrix elements after interpolation
Replies: 1
Views: 6802

Re: Printing complex electron-phonon matrix elements after interpolation

Hi Rachel,

There is no flag to do this in the code. You can modify the subroutine where |g| is written to file.

Best,
Roxana
by roxana
Thu Mar 25, 2021 1:12 pm
Forum: Running the code
Topic: Error in routine mix_broyden(1) :factorization
Replies: 5
Views: 6979

Re: Error in routine mix_broyden(1) :factorization

Hi,

I just noticed that the e-ph coupling strength in your output file is zero. It appears that something went wrong when reading a2f file. So check that the is correct.

"Electron-phonon coupling strength = 0.0000000"

Best,
Roxana
by roxana
Fri Mar 05, 2021 3:19 pm
Forum: General discussion
Topic: about mu* pseudo potential
Replies: 2
Views: 4300

Re: about mu* pseudo potential

Hi,

You can vary mu* between 0.1 and 0.2 and see how Tc changes (most systems have mu* between these limits). As an alternative, you can estimate mu* for your system using Morel-Anderson expression.

Best regards,
Roxana