Improved One-Shot Total Energies from the Linearized GW Density Matrix

Area of Science:

• Computational chemistry
• Quantum chemistry
• Electronic structure theory

Background:

• The linearized GW density matrix (γ^GW) method enhances the static self-energy component in GW calculations.
• γ^GW offers improved Fock operators and total energy components, approaching self-consistent GW quality with single-shot simplicity.

Purpose of the Study:

• To evaluate the performance of the γ^GW method for dimer dissociation, specifically for N₂, LiH, and Be₂.
• To compare γ^GW results with self-consistent GW calculations and assess various total energy functionals.

Main Methods:

• Application of the linearized GW density matrix (γ^GW) method to dimer dissociation.
• Calculation of self-consistent GW results for direct comparison.
• Evaluation of different total energy functionals using non-self-consistent density or density matrix.

Main Results:

• γ^GW approaches self-consistent GW total energies, particularly with a starting point rich in exact exchange.
• While total energy errors are small across functionals, individual energy components show noticeable discrepancies.
• Energy component errors with γ^GW are smaller than those from density functionals.

Conclusions:

• The linearized GW density matrix (γ^GW) method shows promise for improving total energy evaluations within the adiabatic connection framework.
• γ^GW offers a computationally efficient route to high-quality electronic structure calculations.
• Further investigation into energy component accuracy is warranted for advanced computational chemistry applications.