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arXiv · 2512.11410

Renormalization group approach to second-order Green's function theory

Joshua Krieger·Johannes Tölle
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Abstract

In this work, we introduce a new approach for constructing a renormalized and regularized Fock matrix for self-consistent field calculations. The scheme relies on second-order perturbation theory and is conceptually related to quasiparticle self-consistent second-order Green's function theory (GF2). The regularization is derived within the framework of perturbative similarity renormalization group (SRG) theory. By optimizing both the regularization and spin-scaling parameters, we introduce three SRG-qsGF2 variants that enable accurate predictions of quasiparticle energies and dipole moments. Lastly, we demonstrate that formulating second-order perturbation theory for the total electronic energy using the renormalized SRG-qsGF2 Fock matrix as the unperturbed Hamiltonian mitigates divergence problems commonly observed in conventional Møller--Plesset perturbation theory.

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Joshua Krieger, Johannes Tölle. 2026-01-05. Renormalization group approach to second-order Green's function theory. https://arxiv.org/abs/2512.11410

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