2020/07/31 by Oliver J. Backhouse, George H. Booth · 22 citations
Chemistry · Mathematics · Physics and Astronomy · #Advanced Chemical Physics Studies #Hamiltonian (control theory) #Mathematics #Perturbation theory (quantum mechanics) #Photochemistry and Electron Transfer Studies #Physics #Quantum mechanics #Quasiparticle #Renormalization #Spectroscopy and Quantum Chemical Studies #Statistical physics #cond-mat.str-el #physics.chem-ph #physics.comp-ph
paper · pdf · doi:10.1021/acs.jctc.0c00701
published in Journal of Chemical Theory and Computation 16(10), 6294-6304 (American Chemical Society) · 9 pages, 4 figures
arxiv created 2020/08/18 · openalex publication_date 2020/09/04 · arxiv updated 2020/10/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present a self-consistent approach for computing the correlated quasiparticle spectrum of charged excitations in iterative computational time. This is based on the auxiliary second-order Green’s function approach [ Backhouse, O. J. Chem. Theory Comput., 2000 ], in which a self-consistent effective Hamiltonian is constructed by systematically renormalizing the dynamical effects of the self-energy at second-order perturbation theory. From extensive benchmarking across the W4-11 molecular test set, we show that the iterative renormalization and truncation of the effective dynamical resolution arising from the 2 h 1 p and 1 h 2 p spaces can substantially improve the quality of the resulting ionization potential and electron affinity predictions compared to benchmark values. The resulting method is shown to be superior in accuracy to similarly scaling quantum chemical methods for charged excitations in EOM-CC2 and ADC(2), across this test set, while the self-consistency also removes the dependence on the underlying mean-field reference. The approach also allows for single-shot computation of the entire quasiparticle spectrum, which is applied to the benzoquinone molecule and demonstrates the reduction in the single-particle gap due to the correlated physics, and gives direct access to the localization of the Dyson orbitals.