A simple many-body based screening optimization and mixing ansatz for improvement of GW/BSE excitation energies of molecular systems

TL;DR

This paper introduces a straightforward many-body screening mixing method that significantly improves the accuracy of GW/BSE excitation energy predictions for molecules, approaching the results of more complex EOM-CCSD calculations.

Contribution

The paper presents a novel, simple screening mixing strategy that enhances GW/BSE excitation energy predictions by leveraging cancellation effects, reducing the need for computationally intensive methods.

Findings

Achieves near EOM-CCSD accuracy with a simpler approach

Significantly improves GW/BSE excitation energy predictions

Demonstrates effectiveness across molecular systems

Abstract

We propose a simple many-body based screening mixing strategy to considerably enhance the performance of the Bethe-Salpeter (BS) approach for prediction of excitation energies of molecular systems. This strategy enables us to nearly reproduce results of highly correlated equation of motion coupled cluster singles and doubles (EOM-CCSD) through optimal use of cancellation effects.