Dresden 2017 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 29: Electronic Structure Theory: New Concepts and Developments in Density Functional Theory and Beyond - III
MM 29.9: Vortrag
Dienstag, 21. März 2017, 12:45–13:00, GER 38
On the hunt for better functionals in DFT: a new quantum embedding scheme — •Uliana Mordovina1, Teresa E. Reinhard1, Heiko Appel1, and Angel Rubio1,2 — 1Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany — 2Nano-bio Spectroscopy Group and ETSF, Departamento de Fisica de Materiales, Universidad del Pais Vasco UPV/EHU, San Sebastian, Spain
We propose a new systematic technique to derive functionals for standard density functional theory (DFT) in an ab-initio fashion. This technique origins in the recently developed density-matrix embedding theory (DMET) [1]. DMET is a quantum-in-quantum embedding method, which is based on finding a projection between the high-dimensional wave function of the full system and a lower-dimensional wavefunction living in the active space of the embedded system, which is then solved exactly. In the original DMET scope, the projection is improved via optimization of the reduced one-body density matrix. We replace this optimization by a density inversion, exploiting the one-to-one mapping between electronic density and Kohn-Sham potential.
Not only the DMET scheme is improved by the uniqueness of the density-potential mapping, the proposed density-embedding also allows for finding accurate Kohn-Sham potentials. Moreover, unlike in usual DFT, we can systematically improve the description by increasing the size of the active space.
We show benchmark results of our method for molecules in 1D.
[1] G. Knizia, G. K.-L Chan, Phys. Rev. Lett 109, 186404, (2012)