Rigorous Screened Interactions for Realistic Correlated Electron Systems.

Area of Science:

• * Condensed matter physics
• * Quantum chemistry
• * Computational materials science

Background:

• * Traditional static approximations for effective interactions lack quantitative accuracy.
• * Accurately describing electron correlations is crucial for understanding material properties.
• * Quantum embedding methods are powerful for studying complex systems but require accurate effective interactions.

Purpose of the Study:

• * To develop a widely applicable first-principles approach for accurate two-body static effective interactions.
• * To rigorously conserve instantaneous two-point correlation functions.
• * To improve upon uncontrolled static approximations in low-energy Hamiltonians.

Main Methods:

• * Algebraic construction of effective interactions.
• * Application within a quantum embedding framework.
• * Utilizing the random phase approximation for correlation function conservation.

Main Results:

• * Demonstrated quantitative accuracy for effective interactions.
• * Successfully described relaxation of local subspaces in molecular systems via downfolding.
• * Enabled systematic improvement for describing long-range plasmonic contributions in graphene.

Conclusions:

• * The new method provides a robust and accurate way to determine effective interactions.
• * This approach enhances the description of electronic properties in both molecular and extended systems.
• * Offers a systematically improvable framework for future studies in condensed matter and quantum chemistry.