Regensburg 2019 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 12: Frontiers of Electronic-Structure Theory: Focus on the Interface Challenge II (joint session O/CPP/DS/TT)
TT 12.6: Vortrag
Montag, 1. April 2019, 16:15–16:30, H9
Second-order Møller-Plesset perturbation theory and beyond for the band gap and single-particle excitations of solids — •Maria Dragoumi1, Sergey V. Levchenko2,1,3, Igor Ying Zhang4,1, and Matthias Scheffler1 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, DE — 2Skolkovo Innovation Center, Moscow, RU — 3NUST MISIS, Moscow, RU — 4Fudan University, Shanghai, CN
Calculations of the fundamental band-gap and the low-energy excitations of solids are still a challenge for electronic-structure theory. The computationally efficient Kohn-Sham (KS) density functional theory (DFT) with the widely used local or semi-local approximations provides a KS band gap which is much smaller than the fundamental gap. Many-body perturbation theory, on the other hand, addresses the fundamental gap directly. We present here an efficient scalable implementation of Møller-Plesset second order perturbation theory (MP2) for quasi-particle energies [1,2]. By solving the Dyson equation of the single-particle Green’s function, considering self-energy up to second order, we go beyond MP2. The new approach shows a competitive or even superior performance in comparison to the current state-of-the-art methods such as hybrid functionals and GW approximation, where second order exchange is missing. We present numerical results for the band-gap of a wide range of semiconductors and insulators.
[1] J. Sun and R. J. Bartlett, J. Chem. Phys. 104, 8553 (1996).
[2] A. Grüneis, et.al, J. Chem. Phys. 133, 074107 (2010).