The GW/BSE Method in Magnetic Fields

Christof Holzer; Ansgar Pausch; Wim Klopper

doi:10.3389/fchem.2021.746162

The GW/BSE Method in Magnetic Fields

Front Chem. 2021 Nov 25:9:746162. doi: 10.3389/fchem.2021.746162. eCollection 2021.

Authors

Christof Holzer¹, Ansgar Pausch², Wim Klopper^{2

3}

Affiliations

¹ Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
² Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
³ Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.

Abstract

The GW approximation and the Bethe-Salpeter equation have been implemented into the Turbomole program package for computations of molecular systems in a strong, finite magnetic field. Complex-valued London orbitals are used as basis functions to ensure gauge-invariant computational results. The implementation has been benchmarked against triplet excitation energies of 36 small to medium-sized molecules against reference values obtained at the approximate coupled-cluster level (CC2 approximation). Finally, a spectacular change of colour from orange to green of the tetracene molecule is induced by applying magnetic fields between 0 and 9,000 T perpendicular to the molecular plane.

Keywords: Bethe-Salpeter; GW; density functional theory; excitation energy; magnetic field.