Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 106: Frontiers of Electronic Structure Theory: Many-Body Effects, Methods (organized by O)
TT 106.7: Vortrag
Donnerstag, 19. März 2015, 16:45–17:00, MA 004
Green’s Function embedding for Advanced Electronic Structure Methods based on Dynamical Mean-Field Theory — •Wael Chibani1, Xinguo Ren2, Matthias Scheffler1, and Patrick Rinke3 — 1Fritz-Haber-Institute of the Max-Planck-Society, Berlin, Germany — 2Key Laboratory of Quantum Information, USTC, Hefei, China — 3Aalto University, Helsinki, Finland
We introduce an embedding scheme for periodic systems that facilitates a self-consistent treatment of the physically important part of a system with electronic structure methods, that are computationally too expensive for periodic systems. We use dynamical mean-field theory [1] (DMFT) to couple to the rest of the system, which is treated with less demanding approaches such as Kohn-Sham density functional theory. In contrast to the original DMFT formulation for correlated model Hamiltonians, we consider here the unit cell as local embedded cluster in an ab initio way, that includes all electronic degrees of freedom. The performance of our scheme is demonstrated by treating the embedded region with hybrid and GW self-energies (scGW) for simple bulk systems. The total energy and the density of states converge rapidly with respect to the computational parameters and approach their bulk limit with increasing cluster size. For non self-consistent GW calculations we observe Plasmon satellites for Si – in good agreement with periodic G0W0 calculations [2] – that vanish at self-consistency. Our scGW gap of ∼0.9 eV for a two atom unit cell agrees well with previous G0W0 calculations and experiment. [1] A.Georges et al., Rev.Mod.Phys.(2006), [2] M.Guzzo et al., PRL(2011)