First-Principles Description of Charge Transfer in Donor-Acceptor Compounds from Self-Consistent Many-Body Perturbation Theory

Abstract

We investigate charge transfer in prototypical molecular donor-acceptor compounds using hybrid density functional theory (DFT) and the GW approximation at the perturbative level (G0W0) and at full self-consistency (sc-GW). For the systems considered here, no charge transfer should be expected at large intermolecular separation according to photoemission experiment and accurate quantum-chemistry calculations. The capability of hybrid exchange-correlation functionals of reproducing this feature depends critically on the fraction of exact exchange $\alpha$, as for small values of $\alpha$ spurious fractional charge transfer is observed between the donor and the acceptor. G0W0 based on hybrid DFT yields the correct alignment of the frontier orbitals for all values of $\alpha$. However, G0W0 has no capacity to alter the ground-state properties of the system, because of its perturbative nature. The electron density in donor-acceptor compounds thus remains incorrect for small $\alpha$ values. In sc-GW, where the Green's function is obtained from the iterative solution of the Dyson equation, the electron density is updated and reflects the correct description of the level alignment at the GW level, demonstrating the importance of self-consistent many-body approaches for the description of ground- and excited-state properties in donor-acceptor systems.

8 pages, 7 figures

References in corpus (8)

• Resolution-of-identity approach to Hartree-Fock, hybrid density functionals, RPA, MP2, and \textit{GW} with numeric atom-centered orbital basis functions
• Fundamental gaps of finite systems from the eigenvalues of a generalized Kohn-Sham method
• Metallic conduction at organic charge-transfer interfaces
• Combining GW calculations with exact-exchange density-functional theory: An analysis of valence-band photoemission for compound semiconductors
• Unified description of ground and excited states of finite systems: the self-consistent GW approach
• A Benchmark of GW Methods for Azabenzenes: Is the GW Approximation Good Enough?
• Self-consistent GW: All-electron implementation with localized basis functions
• Interface dipoles of organic molecules on Ag(111) in hybrid density-functional theory

Cited by in corpus (13)

• The GW compendium: A practical guide to theoretical photoemission spectroscopy
• Quasi-Particle Self-Consistent $GW$ for Molecules
• Benchmark of GW approaches for the GW100 testset
• Static correlation and electron localization in molecular dimers from the self-consistent RPA and GW approximation
• Many-Body Effects in the X-ray Absorption Spectra of Liquid Water
• Renormalized Singles Green's Function in the T-Matrix Approximation for Accurate Quasiparticle Energy Calculation
• Towards efficient orbital-dependent density functionals for weak and strong correlation
• Length Dependence of Ionization Potentials of Trans-Acetylenes: Internally-Consistent DFT/GW Approach
• Quasi-particle energy spectra in local reduced density matrix functional theory
• Combining Localized Orbital Scaling Correction and Bethe-Salpeter Equation for Accurate Excitation Energies
• Optical absorption spectroscopy probes water wire and its ordering in a hydrogen-bond network
• Full self-consistency versus quasiparticle self-consistency in diagrammatic approaches: Exactly solvable two-site Hubbard Model
• Many-body description of two-dimensional van der Waals ferroelectric $\alpha -$In${}_2$Se${}_3$