mirror of https://github.com/abinit/abinit.git
56 lines
2.9 KiB
Markdown
56 lines
2.9 KiB
Markdown
---
|
|
description: How to compute the matrix elements of the electron-phonon interaction
|
|
authors: MV
|
|
---
|
|
<!--- This is the source file for this topics. Can be edited. -->
|
|
|
|
This page gives hints on how to compute the matrix elements of the electron-phonon interaction with the ABINIT package.
|
|
|
|
## Introduction
|
|
|
|
The theory and details of the implementation are described in [[cite:Gonze2009]] and [[cite:Gonze2016]].
|
|
|
|
Basic calculations of electron-phonon interaction in ABINIT: one performs a
|
|
normal ground state, then DFPT phonon calculations (using [[rfphon]], with
|
|
added keywords [[prepgkk]] and [[prtgkk]], which saves the matrix elements to
|
|
files suffixed GKK. The main change in this respect is that [[prtgkk]] now
|
|
disables the use of symmetry in reducing q-points and perturbations. This
|
|
avoids ambiguities in wave function phases due to band degeneracies. The
|
|
resulting GKK files are merged using the mrggkk utility, and processed by anaddb.
|
|
|
|
With the implementation of phonons in PAW DFPT, the electron phonon coupling
|
|
is also available in PAW, though this has not yet been tested extensively. The
|
|
input variables for electron-phonon coupling in anaddb are described in
|
|
[[cite:Gonze2009]] and [[cite:Gonze2016]].
|
|
|
|
Some details about the calculation of electron-phonon quantities in ABINIT and
|
|
ANADDB can be found [[pdf:elphon_manual.pdf|here]].
|
|
|
|
Subsequently, the GKK file is used to compute many quantities, as explained in
|
|
[[topic:PhononWidth]], [[topic:TDepES]] and [[topic:ElPhonTransport]].
|
|
|
|
A brand new ABINIT driver, focusing on the treatment of electron-phonon
|
|
interaction is under heavy development. Most of the input variables for experts,
|
|
with [[optdriver]]==7 are related to this development. It is operational
|
|
as of v9.2, although the documentation is not yet fully upgraded.
|
|
|
|
## Related Input Variables
|
|
|
|
{{ related_variables }}
|
|
|
|
## Selected Input Files
|
|
|
|
{{ selected_input_files }}
|
|
|
|
## Tutorials
|
|
|
|
* [[tutorial:rf1|The tutorial Response-Function 1 (RF1)]] presents the basics of DFPT calculations within ABINIT. The example given is the study of dynamical and dielectric properties of AlAs (an insulator): phonons at Gamma, dielectric constant, Born effective charges, LO-TO splitting, phonons in the whole Brillouin zone. The creation of the "Derivative Data Base" (DDB) is presented.
|
|
|
|
* (Legacy implementation) [[tutorial:eph_legacy|The legacy tutorial on the electron-phonon interaction]] presents the use of the utility MRGKK and ANADDB to examine the electron-phonon interaction and the subsequent calculation of superconductivity temperature (for bulk systems).
|
|
Also there is a tutorial for [[tutorial:eph_tdep_legacy|the temperature dependence of the electronic structure]]:.
|
|
|
|
* (New implementation) Three tutorials for the new procedure are available at [[tutorial:eph_intro|an overview of the EPH code]],
|
|
[[tutorial:eph4zpr|Zero-point renormalization of the band gap and temperature-dependent band gaps]],
|
|
[[tutorial:eph4mob|Phonon-limited mobility]] and a fourth one is in preparation.
|
|
:.
|