ELPH_TRANSPORT_DRIVER
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.