LPHON POLAR: Difference between revisions
No edit summary |
No edit summary |
||
| Line 14: | Line 14: | ||
{{TAG | LPHON_DISPERSION}}, | {{TAG | LPHON_DISPERSION}}, | ||
{{TAG | PHON_NWRITE}}, | {{TAG | PHON_NWRITE}}, | ||
{{TAG | PHON_DIELECTRIC}}, | {{TAG | PHON_DIELECTRIC}}, | ||
{{TAG | PHON_BORN_CHARGES}}, | {{TAG | PHON_BORN_CHARGES}}, | ||
Revision as of 08:25, 20 July 2022
LPHON_POLAR = .TRUE. | .FALSE.
| Default: LPHON_POLAR | = .FALSE. |
Description: LPHON_POLAR includes dipole-dipole corrections in the computation of the phonon dispersion. For this mode PHON_DIELECTRIC, PHON_BORN_CHARGES must also be set.
If the material is polar (i.e. has more than one different atom type) a special treatment of the long-range dipole-dipole interaction is required to obtain a smooth phonon dispersion. This is activated by setting LPHON_POLAR=.TRUE. and supplying the static dielectric tensor (PHON_DIELECTRIC) and the Born-effective charges (PHON_BORN_CHARGES) which can be obtained on a separate VASP run using the LEPSILON or LCALCEPS tag. The long-range part is evaluated using an Ewald sum with the number of G-vectors in reciprocal space being determined using a cutoff length (PHON_G_CUTOFF).
| Mind: Only available as of VASP 6.3.2. |
Related tags and articles
QPOINTS, LPHON_DISPERSION, PHON_NWRITE, PHON_DIELECTRIC, PHON_BORN_CHARGES, PHON_G_CUTOFF