Question about GPATH.nc and EPH thermoelectric properties

Running Abinit Response calculations
1

Dear Abinit Community,

I am currently using the eph module in Abinit to study carrier mobility and would like to analyze the electron-phonon matrix elements along a specific high-symmetry path. While exploring the abipy gallery examples, I noticed that generating the GPATH.nc file is required. However, I could not find any documentation (including the eph_task tags) or options to produce this file.

My questions are as follows:

  1. How can I generate the GPATH.nc file?
    I have searched the source code and documentation but could not locate any relevant code snippets or output filenames related to GPATH. Should we needs to interpolating DVDB along the high-symmetry path and using eph_task=-2 to compute the matrix elements? I have a similar input file maybe used.
  2. Thermoelectric properties (KAPPA, ZTE files):
    I also noticed that the eph mobility module produces files like KAPPA and ZTE, which appear to be related to thermoelectric calculations. Based on a quick code review, these seem to be implemented via the Onsager coefficient approach. However, I could not find any official Abinit publications or documentation discussing these outputs.
  • Is this a stable/production-ready feature, or is it experimental?
  • Are there any known limitations or references for further reading?

Thank you for your time and assistance!

Best regards,
Kongfer