Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 82: Poster Focus Session: Frontiers of Electronic-Structure Theory - Correlated Electron Materials

O 82.12: Poster

Mittwoch, 14. März 2018, 18:15–20:30, Poster A

Density Response to a Phonon Perturbation from DFPT Using the All-Electron FLAPW Method — •Christian-Roman Gerhorst, Markus Betzinger, Gustav Bihlmayer, Daniel Aaron Klüppelberg, and Stefan Blügel — Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany

A significant milestone in the calculation of phonon dispersions within Density Functional Perturbation Theory (DFPT) is the self-consistent solution of the Sternheimer equation. The resulting expansion coefficients of the response of the wavefunctions describe the linear variation of the density induced by a phonon perturbation. Using the all- electron Full-potential Linearized Augmented Plane-Wave (FLAPW) method, as implemented in the FLEUR code, enables an accurate treatment of complex materials without approximations to the 1/r potential or to the core electrons, but at the expense of additional conceptual challenges due to atom-positioned basis functions. In this contribution, we resolve computational challenges and show results of the self-consistently iterated Sternheimer equation reporting especially on the first variation of the density due to a phonon perturbation. In addition, we briefly shed light on the second-order quantities required for the dynamical matrix and focus on how the choice of the FLAPW method influences the shape of their equations.