EPW v6.0 Release

stiwari · Post by **stiwari** » Thu Aug 21, 2025 7:11 pm

EPW version 6.0 has been released. You can read more regarding the release on the EPW website: https://docs.epw-code.org/doc/Releases.html.

To download and install this version refer to the EPW Download and Install page: https://docs.epw-code.org/doc/DownloadAndInstall.html.

We have implemented multiple new features in EPW v6.0. These features are the following:

Time-dependent Boltzmann transport equation for ultrafast dynamics

Exciton-polaron calculations for self-trapped excitons
- An extensive example of this feature is provided as an example here: https://gitlab.com/epw/q-e/-/tree/devel ... /lif_hdf5?

Two-Level parallelization over both k and q-grids. k -grids are parallelized over pools (inner level) and q-grids are parallelized over images (outer level). With a proper choice of pool and image parallelization one can achieve speedups up to 40x in certain cases
- To run with two-level parallelization use
  Code: Select all
```
mpirun -np <nprocs> epw.x -nk <npool> -ni <nimage> -in epw2.in > epw2.out
```
- It should be noted that
  nprocs= npool* nimage

Printing of both the real and the imaginary part of electron-phonon matrix element when we use prtgkk = True

A more robust Wigner-Seitz search and summation

Apart from new features, we have fixed multiple bugs including:

Population problem when using assume_metal in IBTE calculations

Change in default eps_acoustic (if phonon energy is below eps_acoustic, the electron-phonon interactions are ignored for such modes) from 0.5 meV to 0.01 meV