Dresden 2017 – wissenschaftliches Programm
MM 35: Electronic Structure Theory: New Concepts and Developments in Density Functional Theory and Beyond
MM 35.2: Poster
Dienstag, 21. März 2017, 18:30–20:30, P2-OG4
DFPT within the All-Electron FLAPW Method: Application to Phonons — •Christian-Roman Gerhorst, Markus Betzinger, Gustav Bihlmayer, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
In all-electron methods based on Density Functional Theory, typically the Finite Displacement approach is employed when describing the effect of a phonon perturbation on an electronic many-particle system. In difference to this common procedure, we implement the considerably more effective Density Functional Perturbation Theory (DFPT) into our full-potential linearized augmented plane-wave (FLAPW) code FLEUR; i.e. an all-electron code avoiding any approximation to the shape of the potential including the 1 / r singularity. This is a non-trivial problem, because we have to tackle a position-dependent basis set generating additional Pulay and surface terms beyond the contributions known for force calculations when atoms are displaced. In this contribution, we report about the key challenge to the realization of the DFPT, which is the self-consistent solution of the Sternheimer equation providing the linear response of the electron density to a phonon perturbation. In a next step, we will use these results to construct the Dynamical Matrix encoding all relevant phonon information to shed light on the phonon-related properties of electronic many-particle systems.