Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 58: Poster Session III (Solid-liquid interfaces; Scanning probe and other methods; Electronic structure theory; Spin-orbit interaction)

O 58.68: Poster

Mittwoch, 13. März 2013, 18:15–21:45, Poster B1

Effects of electron-phonon coupling on excitation spectra — •Honghui Shang, Christian Carbogno, Patrick Rinke, and Matthias Scheffler — Fritz-Haber-Institut der MPG, Berlin

The electron-phonon interaction plays a crucial role in many areas of physics. The main purpose of our study is to investigate the effect of the electron-phonon coupling on the excitation spectra of (organic) molecules and solids. For example, the phonon induced renormalization of electronic excitations can be as large as a few tenths of an eV for diamond and similar magnitudes are expected for other materials such as SiC, GaN, ZnO. To incorporate electron-phonon effects from first principles we employ a Green function/self-energy framework. Here we present an implementation for the electron-phonon coupling matrix elements in the all-electron Fritz Haber Institut ab initio molecular simulations (FHI-aims) package [1]. For the calculations of the first-order density response, both the coupled-perturbed self-consistent field method and density functional perturbation theory have been implemented. By comparing with the results from finite differences, the accuracy of the first-order response in the Hamiltonian and the density is demonstrated for both methods. With the first-order density response, the electron-phonon coupling matrix elements are then calculated using numeric atom-centered orbital (NAO) basis sets. Due to the spatial locality of the NAO basis set, we anticipate our approach be applicable to large systems up to hundreds of atoms.

[1] https://aimsclub.fhi-berlin.mpg.de/