is SCDFT method available in ELK code?

[Farhad Jalali_Asadabadi]

Dear ELK Developers and Users Community,

I trust this message finds you well.

I have been exploring the capabilities of ELK for my ongoing work and I'm particularly intrigued by the Superconducting Density Functional Theory (SCDFT) method. I have a query concerning the connection between SCDFT, DFPT, and the supercell method.

Are the latter two methods, DFPT and supercell, distinct from SCDFT or are they connected in some way? Are the recent functionals such as LM205 and the one introduced in 2020 implemented as part of the SCDFT method or are they separate entities?

I would like to utilize the SCDFT method in my calculations. Could you kindly provide guidance on how to do so if it is distinct from the DFPT and supercell methods?

Your insights and guidance will be greatly appreciated.

Best regards,

Farhad

[J. K. Dewhurst]

Dear Farhad,

The SCDFT method is not implemented in Elk.

However, there are three alternatives:
1. McMillan-Allen-Dynes superconducting critical temperature
2. Isotropic Eliashberg equations
3. Electron-phonon coupled Bogoliubov equations [Phys. Rev. B 105, 174509 (2022)]

All these use the phonons and electron-phonon coupling matrix elements calculated either with the supercell method or DFPT.

Regards,
Kay.