Renormalization group approach to second-order Green's function theory
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 M{\o}ller--Plesset perturbation theory.
Keywords
Cite
@article{arxiv.2512.11410,
title = {Renormalization group approach to second-order Green's function theory},
author = {Joshua Krieger and Johannes Tölle},
journal= {arXiv preprint arXiv:2512.11410},
year = {2026}
}