ELPH POT LATTICE: Difference between revisions

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Once the electron-phonon potential [[Electron-phonon_potential_from_supercells|has been computed in the supercell]], it needs to be mapped to the primitive cell.
Once the electron-phonon potential [[Electron-phonon_potential_from_supercells|has been computed in the supercell]], it needs to be mapped to the primitive cell.
By default, VASP performs this mapping for the primitive cell that is found by the symmetry routines and reported in the {{FILE|OUTCAR}} file.
This is done via {{TAGO|ELPH_POT_GENERATE|True}}.
By default, VASP performs the mapping for the primitive cell that is found by the symmetry routines and that is reported in the {{FILE|OUTCAR}} file.
In cases where the primitive cell needs to be specified manually, {{TAG|ELPH_POT_LATTICE}} can be used.
In cases where the primitive cell needs to be specified manually, {{TAG|ELPH_POT_LATTICE}} can be used.


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These lattice vectors are then used to construct the primitive-cell information in the {{FILE|phelel_params.hdf5}} file.
These lattice vectors are then used to construct the primitive-cell information in the {{FILE|phelel_params.hdf5}} file.
{{NB|mind|The supplied lattice vectors must span a valid primitive cell of the supercell or the code will exit with an error.}}
{{NB|mind|The supplied lattice vectors must span a valid primitive cell of the supercell or the code will exit with an error.}}
{{NB|mind|The supplied lattice vectors must then also be used as the primitive-cell {{FILE|POSCAR}} for the electron-phonon calculation.}}
{{NB|tip|The primitive cell used for mapping is also written to the {{FILE|CONTCAR_ELPH}} file, which can conveniently be used as the {{FILE|POSCAR}} input for the subsequent electron-phonon calculation. This ensures that the primitive-cell calculation is consistent with the information in the {{FILE|phelel_params.hdf5}} file.}}


==Related tags and articles==
==Related tags and articles==
{{TAG | ELPH_POT_GENERATE}},
* {{TAG | ELPH_POT_GENERATE}}
{{TAG | ELPH_POT_FFT_MESH}},
* {{TAG | ELPH_POT_FFT_MESH}}
{{FILE | phelel_params.hdf5}}
* {{FILE | phelel_params.hdf5}}
* {{FILE | CONTCAR_ELPH}}


[[Category:INCAR tag]][[Category:Electron-phonon_interactions]]
[[Category:INCAR tag]][[Category:Electron-phonon_interactions]]

Revision as of 16:19, 27 February 2025

ELPH_POT_LATTICE = [3x3 real] 

Description: Allows specifying an alternative primitive cell for the mapping of the electron-phonon potential.

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. This is done via ELPH_POT_GENERATE = True. By default, VASP performs the mapping for the primitive cell that is found by the symmetry routines and that is reported in the OUTCAR file. In cases where the primitive cell needs to be specified manually, ELPH_POT_LATTICE can be used.

ELPH_POT_LATTICE = a1x a1y a1z a2x a2y a2z a3x a3y a3z specifies the three primitive lattice vectors , and in Cartesian coordinates. These lattice vectors are then used to construct the primitive-cell information in the phelel_params.hdf5 file.

Mind: The supplied lattice vectors must span a valid primitive cell of the supercell or the code will exit with an error.
Tip: The primitive cell used for mapping is also written to the CONTCAR_ELPH file, which can conveniently be used as the POSCAR input for the subsequent electron-phonon calculation. This ensures that the primitive-cell calculation is consistent with the information in the phelel_params.hdf5 file.

Related tags and articles