ELPH_SCATTERING_APPROX
ELPH_SCATTERING_APPROX = [string]
Default: ELPH_SCATTERING_APPROX = SERTA MRTA_LAMBDA
Description: Select which type of approximation is used to compute the electron scattering lifetimes due to electron-phonon coupling
There are different approximations to compute the electronic lifetimes due to electron-phonon scattering. Each of these can lead to significantly different transport coefficients.
Options to select
ELPH_SCATTERING_APPROX = CRTA- Constant Relaxation-Time Approximation- The relaxation time is assumed constant. It needs to be specified via TRANSPORT_RELAXATION_TIME. In this case, the computation of electron-phonon matrix elements is skipped entirely, which is a huge performance boost compared to the other relaxation-time approximations.
| Warning: While the CRTA can be a reasonable approximation for metals, it will generally fail for insulators. |
ELPH_SCATTERING_APPROX = SERTA- Self-Energy Relaxation-Time Approximation- Calculates the relaxation time from the imaginary part of the electron self-energy.
ELPH_SCATTERING_APPROX = ERTA_LAMDBA- Energy Relaxation-Time Approximation (mean-free path approximation)ELPH_SCATTERING_APPROX = ERTA_TAU- Energy Relaxation-Time Approximation (lifetime approximation)ELPH_SCATTERING_APPROX = MRTA_LAMDBA- Momentum Relaxation-Time Approximation (mean-free path approximation)ELPH_SCATTERING_APPROX = MRTA_TAU- Momentum Relaxation-Time Approximation (lifetime approximation)