ELPH TRANSPORT DRIVER: Difference between revisions
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Description: choose method to compute the Onsager coefficients, which are then used to compute the transport coefficients. | Description: choose method to compute the Onsager coefficients, which are then used to compute the transport coefficients. | ||
{{Available|6.5.0}} | |||
---- | ---- | ||
The | The Onsager coefficients can be computed using either of the options bellow, each with its own advantages and disadvantages. | ||
They are defined as | |||
:<math> | |||
L_{ij} = \int d\epsilon \, \sigma(\epsilon) \, | |||
(\epsilon-\mu)^{i+j-2} | |||
\left( -\frac{\partial f^0}{\partial \epsilon} \right), | |||
</math> | |||
where <math>\sigma(\epsilon)</math> is the transport distribution function, | |||
<math>\mu</math> the chemical potential, and <math>f^0</math> the Fermi–Dirac distribution. | |||
; {{TAGO|ELPH_TRANSPORT_DRIVER|1|op==}} | ; {{TAGO|ELPH_TRANSPORT_DRIVER|1|op==}} | ||
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; {{TAGO|ELPH_TRANSPORT_DRIVER|2|op==}} | ; {{TAGO|ELPH_TRANSPORT_DRIVER|2|op==}} | ||
: Use Gauss-Legendre integration to evaluate the Onsager coefficients. The convergence of the integral can be checked by performing a convergence study with respect to {{TAG|TRANSPORT_NEDOS}} alone. | : Use Gauss-Legendre integration to evaluate the Onsager coefficients. The convergence of the integral can be checked by performing a convergence study with respect to {{TAG|TRANSPORT_NEDOS}} alone. | ||
==Related tags and articles== | |||
* [[Transport coefficients including electron-phonon scattering|Transport calculations]] | |||
* {{TAG|ELPH_RUN}} | |||
* {{TAG|ELPH_TRANSPORT}} | |||
* {{TAG|TRANSPORT_NEDOS}} | |||
* {{TAG|ELPH_TRANSPORT_DFERMI_TOL}} | |||
* {{TAG|ELPH_TRANSPORT_EMIN}} | |||
* {{TAG|ELPH_TRANSPORT_EMAX}} | |||
[[Category:INCAR tag]][[Category:Electron-phonon_interactions]] | |||
Latest revision as of 11:17, 12 September 2025
ELPH_TRANSPORT_DRIVER = [integer]
Default: ELPH_TRANSPORT_DRIVER = ELPH_TRANSPORT_DRIVER
Description: choose method to compute the Onsager coefficients, which are then used to compute the transport coefficients.
| Mind: Available as of VASP 6.5.0 |
The Onsager coefficients can be computed using either of the options bellow, each with its own advantages and disadvantages. They are defined as
- [math]\displaystyle{ L_{ij} = \int d\epsilon \, \sigma(\epsilon) \, (\epsilon-\mu)^{i+j-2} \left( -\frac{\partial f^0}{\partial \epsilon} \right), }[/math]
where [math]\displaystyle{ \sigma(\epsilon) }[/math] is the transport distribution function, [math]\displaystyle{ \mu }[/math] the chemical potential, and [math]\displaystyle{ f^0 }[/math] the Fermi–Dirac distribution.
ELPH_TRANSPORT_DRIVER = 1- Use a linear grid of energies with TRANSPORT_NEDOS in the interval determined by ELPH_TRANSPORT_DFERMI_TOL or ELPH_TRANSPORT_EMIN and ELPH_TRANSPORT_EMAX and the Simpson integration rule to evaluate the Onsager coefficients.
ELPH_TRANSPORT_DRIVER = 2- Use Gauss-Legendre integration to evaluate the Onsager coefficients. The convergence of the integral can be checked by performing a convergence study with respect to TRANSPORT_NEDOS alone.