ELPH SELFEN DELTA: Difference between revisions
Created page with "{{elph_release}} {{DISPLAYTITLE:ELPH_SELFEN_DELTA}} {{TAGDEF|ELPH_SELFEN_DELTA|[real array]| 0.01}} Description: Complex imaginary shift to use when computing the self-energy due to electron-phonon coupling. ---- If the value is set to 0.0 then the tetrahedron method is used to perform the Brillouin zone integrals and evaluate only the imaginary part of the electron self-energy. This is the recommended option for Transport coefficients including electron-phonon scatt..." |
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{{DISPLAYTITLE:ELPH_SELFEN_DELTA}} | {{DISPLAYTITLE:ELPH_SELFEN_DELTA}} | ||
{{TAGDEF|ELPH_SELFEN_DELTA|[real array]| 0.01}} | {{TAGDEF|ELPH_SELFEN_DELTA|[real array]| 0.01}} | ||
Description: Complex imaginary shift to use when computing the self-energy due to electron-phonon coupling. | Description: Complex imaginary shift to use when computing the self-energy due to electron-phonon coupling. | ||
{{Available|6.5.0}} | |||
---- | ---- | ||
If the value is set to 0.0 then the tetrahedron method is used to perform the Brillouin zone integrals and evaluate only the imaginary part of the electron self-energy. This is the recommended option for [[Transport coefficients including electron-phonon scattering|transport calculations]]. | If the value is set to 0.0 then the tetrahedron method is used to perform the Brillouin zone integrals and evaluate only the imaginary part of the electron self-energy. This is the recommended option for [[Transport coefficients including electron-phonon scattering|transport calculations]]. A finite value instead replaces the exact tetrahedron integration with a Lorentzian smearing of width {{TAG|ELPH_SELFEN_DELTA}} around the [[Electron-phonon interactions theory#Electron_self-energy|Fan self-energy]] pole, which can likewise be used for transport calculations. | ||
For [[Bandgap renormalization due to electron-phonon coupling| bandgap renormalization]] since one is mainly interested in the real part of the self-energy due to electron-phonon coupling, a small finite value should be used and a dense <b>k</b> point mesh used. | For [[Bandgap renormalization due to electron-phonon coupling| bandgap renormalization]] since one is mainly interested in the real part of the self-energy due to electron-phonon coupling, a small finite value should be used and a dense <b>k</b> point mesh used. | ||
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If more than one value is specified, the number of self-energy accumulators is increased such that one exists for each value in this array. | If more than one value is specified, the number of self-energy accumulators is increased such that one exists for each value in this array. | ||
It is possible to compute the self-energy using the tetrahedron method and a finite complex shift in the same run. | It is possible to compute the self-energy using the tetrahedron method and a finite complex shift in the same run. | ||
==Related tags and articles== | |||
* [[Bandgap renormalization due to electron-phonon coupling|Bandstructure renormalization]] | |||
* {{TAG|ELPH_RUN}} | |||
* {{TAG|ELPH_SELFEN_GAPS}} | |||
* {{TAG|ELPH_SELFEN_FAN}} | |||
* {{TAG|ELPH_SELFEN_STATIC}} | |||
[[Category:INCAR tag]][[Category:Electron-phonon_interactions]] | |||
Latest revision as of 14:45, 10 July 2026
ELPH_SELFEN_DELTA = [real array]
Default: ELPH_SELFEN_DELTA = 0.01
Description: Complex imaginary shift to use when computing the self-energy due to electron-phonon coupling.
| Mind: Available as of VASP 6.5.0 |
If the value is set to 0.0 then the tetrahedron method is used to perform the Brillouin zone integrals and evaluate only the imaginary part of the electron self-energy. This is the recommended option for transport calculations. A finite value instead replaces the exact tetrahedron integration with a Lorentzian smearing of width ELPH_SELFEN_DELTA around the Fan self-energy pole, which can likewise be used for transport calculations.
For bandgap renormalization since one is mainly interested in the real part of the self-energy due to electron-phonon coupling, a small finite value should be used and a dense k point mesh used.
If more than one value is specified, the number of self-energy accumulators is increased such that one exists for each value in this array. It is possible to compute the self-energy using the tetrahedron method and a finite complex shift in the same run.