A reformulation of site-occupation embedding theory (SOET) in terms of Green's functions is presented. Referred to as site-occupation Green's-function embedding theory (SOGET), this extension of density-functional theory for model Hamiltonians shares many features with dynamical mean-field theory but is formally exact (in any dimension). In SOGET, the impurity-interacting correlation potential becomes a density-functional self-energy which is frequency dependent and in principle nonlocal. A simple local-density-functional approximation (LDA) combining the Bethe ansatz LDA with the self-energy of the two-level Anderson model is constructed and successfully applied to the one-dimensional Hubbard model. Unlike in previous implementations of SOET, no many-body wave function is needed, thus reducing drastically the computational cost of the method.

• Received 2 August 2019
• Revised 10 October 2019

DOI:https://doi.org/10.1103/PhysRevB.100.195104