LRPA: Difference between revisions
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Description: {{TAG|LRPA}}=.TRUE. includes local field effect on the Hartree level only. | Description: {{TAG|LRPA}}=.TRUE. includes local field effect on the Hartree level only. | ||
---- | ---- | ||
For {{TAG|LRPA}}=.TRUE. local field | For {{TAG|LRPA}}=.TRUE. local field effects are included on the Hartree level only. This means that cell periodic microscopic changes of the local potential related to the change of the Hartree potential are included. | ||
For {{TAG|LRPA}}=.FALSE. changes of the Hartree ''and the exchange correlation potential'' are included. This usually increases the dielectric constants. The final values for the dielectric tensor can be found in the {{TAG|OUTCAR}} file after the lines. | For {{TAG|LRPA}}=.FALSE. changes of the Hartree ''and the exchange-correlation potential'' are included. This usually increases the dielectric constants. The final values for the dielectric tensor can be found in the {{TAG|OUTCAR}} file after the lines. | ||
MACROSCOPIC STATIC DIELECTRIC TENSOR (including local field effects in RPA (Hartree)) | MACROSCOPIC STATIC DIELECTRIC TENSOR (including local field effects in RPA (Hartree)) | ||
For {{TAG|LRPA}}=.FALSE. the dielectric tensor is written after the lines: | For {{TAG|LRPA}}=.FALSE. the dielectric tensor is written after the lines: | ||
MACROSCOPIC STATIC DIELECTRIC TENSOR (including local field effects in DFT) | MACROSCOPIC STATIC DIELECTRIC TENSOR (including local field effects in DFT) | ||
The dielectric tensor ''excluding'' local field effects is always calculated ( | The dielectric tensor ''excluding'' local field effects is always calculated (regardless of {{TAG|LRPA}}). The piezoelectric tensors and the Born effective charges as well as the ionic contributions the to dielectric tensor are only calculated for {{TAG|LRPA}}=.FALSE.. | ||
{{NB|warning|We recommend using the {{TAG|LRPA}} tag only in combination with {{TAG|LEPSILON}} or {{TAG|LCALCEPS}}, where the treatment of the terms beyond RPA is unambiguous. In the [[many-body perturbation theory|MBPT calculations]] various approximations beyond RPA can be used, hence more precise control of the included terms should be used via the tags {{TAG|LHARTREE}}, {{TAG|LADDER}}, and {{TAG|LFXC}}.}} | |||
== Related | == Related tags and articles == | ||
{{TAG|LEPSILON}}, | {{TAG|LEPSILON}}, | ||
{{TAG|LCALCEPS}}, | {{TAG|LCALCEPS}}, | ||
{{TAG|LHARTREE}}, | {{TAG|LHARTREE}}, | ||
{{TAG|LADDER}} | {{TAG|LADDER}}, | ||
{{TAG|LFXC}} | |||
{{sc|LRPA|Examples|Examples that use this tag}} | {{sc|LRPA|Examples|Examples that use this tag}} | ||
---- | ---- | ||
[[Category:INCAR]][[Category:Linear response]] | [[Category:INCAR tag]][[Category:Linear response]][[Category:Dielectric properties]] | ||
Latest revision as of 05:35, 14 June 2024
LRPA = .TRUE. | .FALSE.
Default: LRPA = .FALSE.
Description: LRPA=.TRUE. includes local field effect on the Hartree level only.
For LRPA=.TRUE. local field effects are included on the Hartree level only. This means that cell periodic microscopic changes of the local potential related to the change of the Hartree potential are included.
For LRPA=.FALSE. changes of the Hartree and the exchange-correlation potential are included. This usually increases the dielectric constants. The final values for the dielectric tensor can be found in the OUTCAR file after the lines.
MACROSCOPIC STATIC DIELECTRIC TENSOR (including local field effects in RPA (Hartree))
For LRPA=.FALSE. the dielectric tensor is written after the lines:
MACROSCOPIC STATIC DIELECTRIC TENSOR (including local field effects in DFT)
The dielectric tensor excluding local field effects is always calculated (regardless of LRPA). The piezoelectric tensors and the Born effective charges as well as the ionic contributions the to dielectric tensor are only calculated for LRPA=.FALSE..
| Warning: We recommend using the LRPA tag only in combination with LEPSILON or LCALCEPS, where the treatment of the terms beyond RPA is unambiguous. In the MBPT calculations various approximations beyond RPA can be used, hence more precise control of the included terms should be used via the tags LHARTREE, LADDER, and LFXC. |
Related tags and articles
LEPSILON, LCALCEPS, LHARTREE, LADDER, LFXC