ELPH POT FFT MESH: Difference between revisions
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Description: Specifies the FFT mesh for mapping the electron-phonon potential to the primitive cell. | Description: Specifies the FFT mesh for mapping the electron-phonon potential to the primitive cell. | ||
{{Available|6.5.0}} | |||
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Latest revision as of 14:22, 17 January 2025
ELPH_POT_FFT_MESH = [real real real]
Description: Specifies the FFT mesh for mapping the electron-phonon potential to the primitive cell.
| Mind: Available as of VASP 6.5.0 |
Once the electron-phonon potential has been computed in the supercell, it needs to be mapped to the primitive cell. By default, VASP chooses the primitive-cell FFT mesh to be consistent with the current ENCUT. However, sometimes it might be necessary to specify the FFT grid dimensions manually via ELPH_POT_FFT_MESH.
The chosen values must be the same as the desired NGX, NGY and NGZ of the electron-phonon calculation in the primitive cell.
| Tip: In order to find the FFT grid dimensions corresponding to the primitive cell, you can start a minimal VASP calculation in the primitive cell and extract the values for NGX, NGY and NGZ from the OUTCAR file. |