Error calculating transport properties using SERTA

[ghaithjamal_nadhreen]

Hello,

I have been trying to calculate the transport properties using the SERTA ELPH_SCATTERING_APPROX. The calculations crash with an error about failing to open the phelel_params.hdf5 file. When I checked the files, it turns out VASP did not generate the phelel_params.hdf5 file. I have checked the wiki and made sure to include the "ELPH_POT_GENERATE = True" tag to generate the file. Nevertheless, it was not created.

Next, I tried using the phelel package and generated the phelel_params.hdf5 file separately. However, when VASP reached the ELPH step it crashed again with no error in the standard output file but reported a bug in the standard error file and asked to file a bug report.

I have attached the my files. Maybe I am doing something wrong. Your support is greatly appreciated.

Thank you

[manuel_engel1]

Hello,

Thanks for reaching out. Running the electron-phonon code in VASP is at minimum a two-step process. A brief overview of the workflow is given on the electron-phonon caterogy page.

The generation of the phelel_params.hdf5 is the first step of the process and it requires a supercell (you will have to make sure that this cell is large enough by converging the final result with respect to the supercell size). You can do this either via ELPH_POT_GENERATE or via the phelel method, as detailed here. You must not set any of the electron-phonon tags related to transport. The transport calculation comes in the second step which uses a unit cell.

The second step is the actual electron-phonon calculation. This step requires the phelel_params.hdf5 file as input. In this step, we use a primitive cell (this primitive cell must match the unit cell found during the previous supercell calculation, or you specify it explicitly using ELPH_POT_LATTICE during the previous step). This is where you can follow the documentation on calculating transport coefficients.

Let me know if that works for you.

[ghaithjamal_nadhreen]

Thank you for the reply. I followed the instructions from your reply. However, in the first step after the finite difference stages were done I got this error message: "SmithNormalForm routine failed because the input matrix had a negative determinant". What does this error mean? Maybe my supercell is not large enough?

Thank you.

[manuel_engel1]

This is a bit unexpected. It might be due to a bug, but I will look into it. I'm sorry for the inconvenience caused by this issue.

In the meantime, could you send me your input files for this new calculation? I would like to reproduce it on my end, so that we can include a potential fix in the upcoming patch release.

[ghaithjamal_nadhreen]

Thank you for your support. I have attached my input files.