Large Scale Bethe-Salpeter Equation Calculations

ORAL

Abstract

We present an efficient method to solve the Bethe-Salpeter equation (BSE) to compute electron-hole excitations and optical spectra of systems with hundreds of electrons, including molecules and solids. The method does not require the explicit evaluation of virtual electronic states, nor the inversion of dielectric matrices; its computational workload scales as the third power of the number of electrons in the system. We computed density response functions in finite field, and used localized Kohn-Sham orbitals, as obtained by the bisection method [1]. The approach is implemented by coupling the Qbox [http://qboxcode.org] and WEST [http://www.west-code.org] codes. Results for the excitonic binding energies and optical absorption spectra of the Thiel molecular set, and for condensed systems of unprecedented size, including water and ice samples with hundreds of electrons, will be discussed. Ref. [1] François Gygi, PRL 102, 166406 (2009).

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Presenters

  • Ngoc Linh Nguyen

    Institute for Molecular Engineering, University of Chicago

Authors

  • Ngoc Linh Nguyen

    Institute for Molecular Engineering, University of Chicago

  • He Ma

    Chemistry Department, University of Chicago, Institute for Molecular Engineering, University of Chicago, Department of Chemistry and Institute for Molecular Engineering, University of Chicago

  • Marco Govoni

    Materials Science Division, Argonne National Laboratory, Institute for Molecular Engineering and Materials Science Division, Argonne National Lab, Argonne National Laboratory; University of Chicago, Insitute for Molecular Engineering and Materials Science Division, Argonne National Lab, Materials Science Division , Argonne National Laboratory, Argonne National Laboratory, Institute for Molecular Engineering, University of Chicago

  • Francois Gygi

    Department of Computer Science, University of California Davis, University of California, Davis, Univ of California - Davis

  • Giulia Galli

    Institute for Molecular Engineering, University of Chicago, Univ of Chicago, University of Chicago, Institute for Molecular Engineering, University of Chicago; Argonne National Laboratory, Institute for Molecular Engineering, University of Chicago, Chicago, IL, United States and Materials Science Division, Argonne National Laboratory, University of Chicago; Argonne National Laboratory, Institute for Molecular Engineering, Univ of Chicago