EPW Forum

Posted: **Tue Oct 28, 2025 11:57 am**

Dear all,

I would like to ask if there is any significant difference between the results obtained from EPW 5.9 and EPW 6.0, particularly regarding the HDF5 build and exciton–phonon coupling implementation.

The reason for my doubt is the appearance of an additional message in EPW 6.0 after successful Wannierization, related to HDF5 build configuration, which is absent in EPW 5.9.

1. EPW 6.0 (HDF5 Enabled)

: PARAM_HDF5_Enabled_.jpg (53.58 KiB) Viewed 1867 times

2. EPW 6.0 (HDF5 Disabled)

: PARAM_HDF5_Disabled_.jpg (56.82 KiB) Viewed 1867 times

3. EPW 5.9 (No HDF5)

: KAUST_NO_HDF5.jpg (74.92 KiB) Viewed 1867 times

Posted: **Wed Oct 29, 2025 10:16 pm**

Hi Agathyan,

There will be no significant difference in results. The exciton-phonon coupling only works when you enable HDF5.

In EPW5.9, the exciton-phonon was not implemented. The warning is added to notify the user that if you want to use exciton-phonon, you need to use HDF5.

Without seeing any difference in your results, it will be hard to suggest.

Regards,
Shashi

EPW Forum

Does enabling HDF5 in EPW 6.0 affect results compared to EPW 5.9?

Does enabling HDF5 in EPW 6.0 affect results compared to EPW 5.9?

Re: Does enabling HDF5 in EPW 6.0 affect results compared to EPW 5.9?