# Testing self-energy embedding theory in combination with GW

## TL;DR

This paper introduces a self-energy embedding theory combining GW and configuration interaction methods, demonstrating its accuracy and systematic improvability for molecular systems with both weak and strong correlations.

## Contribution

It develops a new SEET framework integrating GW and CI, providing a controlled approach for treating correlations in molecules.

## Key findings

- SEET(CI/GW) yields accurate results for molecular systems.
- The method produces well-behaved causal self-energies and Green's functions.
- Comparison with GW+DMFT highlights differences in correlation treatment.

## Abstract

We present a theoretical framework and implementation details for self-energy embedding theory (SEET) with the GW approximation for the treatment of weakly correlated degrees of freedom and configuration interactions solver for handing the strongly correlated degrees. On a series of molecular examples, for which the exact results are known within a given basis, we demonstrate that SEET(CI/GW) is a systematically improvable and well controlled method capable of giving accurate results and well behaved causal self-energies and Green's functions. We compare the theoretical framework of SEET(CI/GW) to that of GW+DMFT and comment on differences between these to approaches that aim to treat both strongly and weakly correlated simultaneously.