PHON DIELECTRIC: Difference between revisions
(Created page with "{{TAGDEF|PHON_DIELECTRIC| [3x3 real] }} {{DEF|PHON_DIELECTRIC|None|}} Description: {{TAG|PHON_DIELECTRIC}} sets the static dielectric tensor to be used for the dipole-dipole...") |
No edit summary |
||
| (7 intermediate revisions by 2 users not shown) | |||
| Line 1: | Line 1: | ||
{{DISPLAYTITLE:PHON_DIELECTRIC}} | |||
{{TAGDEF|PHON_DIELECTRIC| [3x3 real] }} | {{TAGDEF|PHON_DIELECTRIC| [3x3 real] }} | ||
{{DEF|PHON_DIELECTRIC|None|}} | {{DEF|PHON_DIELECTRIC|None|}} | ||
| Line 5: | Line 6: | ||
---- | ---- | ||
If the material is polar (i.e. | If the material is non-metallic and polar (i.e. two or more atoms in the unit cell carry nonzero Born effective charge tensors), a special treatment of the long-range dipole-dipole interaction is required to obtain a smooth phonon dispersion. | ||
This is activated by setting {{TAG|LPHON_POLAR}}=.TRUE. and supplying the static dielectric tensor ({{TAG|PHON_DIELECTRIC}}) and the Born-effective charges ({{TAG|PHON_BORN_CHARGES}}) which can be obtained | This is activated by setting {{TAG|LPHON_POLAR}}=.TRUE. and supplying the static dielectric tensor ({{TAG|PHON_DIELECTRIC}}) and the Born-effective charges ({{TAG|PHON_BORN_CHARGES}}) which can be obtained in a separate VASP calculation using the {{TAG|LEPSILON}} or {{TAG|LCALCEPS}} tag. | ||
The dipole-dipole part of the interatomic force-constants is evaluated using an Ewald summation with the number of <math>\mathbf{G}</math> vectors determined by the cutoff length ({{TAG|PHON_G_CUTOFF}}). | |||
{{NB|mind| Only available as of VASP 6.3.2.}} | {{NB|mind| Only available as of VASP 6.3.2.}} | ||
| Line 14: | Line 16: | ||
{{TAG | PHON_NWRITE}}, | {{TAG | PHON_NWRITE}}, | ||
{{TAG | LPHON_POLAR}}, | {{TAG | LPHON_POLAR}}, | ||
{{TAG | PHON_BORN_CHARGES}}, | {{TAG | PHON_BORN_CHARGES}}, | ||
{{TAG | PHON_G_CUTOFF | {{TAG | PHON_G_CUTOFF}} | ||
{{sc|PHON_DIELECTRIC|Examples|Examples that use this tag}} | {{sc|PHON_DIELECTRIC|Examples|Examples that use this tag}} | ||
[[Category:INCAR tag]][[Category:Phonons]] | [[Category:INCAR tag]][[Category:Phonons]] | ||
Latest revision as of 10:35, 23 October 2023
PHON_DIELECTRIC = [3x3 real]
| Default: PHON_DIELECTRIC | = None |
Description: PHON_DIELECTRIC sets the static dielectric tensor to be used for the dipole-dipole corrections in the computation of the phonon dispersion. This is only used when LPHON_POLAR=.TRUE.
If the material is non-metallic and polar (i.e. two or more atoms in the unit cell carry nonzero Born effective charge tensors), 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 in a separate VASP calculation using the LEPSILON or LCALCEPS tag. The dipole-dipole part of the interatomic force-constants is evaluated using an Ewald summation with the number of vectors determined by the cutoff length (PHON_G_CUTOFF).
| Mind: Only available as of VASP 6.3.2. |
Related tags and articles
QPOINTS, LPHON_DISPERSION, PHON_NWRITE, LPHON_POLAR, PHON_BORN_CHARGES, PHON_G_CUTOFF