LPHON POLAR: Difference between revisions
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{{DEF|LPHON_POLAR|.FALSE.|}} | {{DEF|LPHON_POLAR|.FALSE.|}} | ||
Description: {{TAG|LPHON_POLAR}} includes dipole-dipole corrections in the computation of the phonon dispersion. For this mode {{TAG|PHON_DIELECTRIC}} | Description: {{TAG|LPHON_POLAR}} includes dipole-dipole corrections in the computation of the phonon dispersion. For this mode, {{TAG|PHON_DIELECTRIC}} and {{TAG|PHON_BORN_CHARGES}} must also be set. | ||
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Revision as of 09:23, 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 and 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