Electron correlation in solids via density embedding theory.

Area of Science:

• Quantum chemistry
• Condensed matter physics
• Computational materials science

Background:

• Density matrix embedding theory (DMET) and density embedding theory (DET) have been developed for model systems.
• Accurate electronic structure calculations for infinite systems remain computationally demanding.

Purpose of the Study:

• To extend DMET/DET formalism to the ab initio description of infinite systems.
• To develop an efficient method for calculating electronic structures of extended materials.

Main Methods:

• Formulation of an impurity Hamiltonian for infinite systems.
• Application of coupled cluster theory as an impurity solver.
• Utilizing Wannier functions without requiring localization of unoccupied bands.

Main Results:

• Demonstrated applicability in 1, 2, and 3 dimensions.
• Achieved results comparable to traditional coupled cluster calculations for infinite systems.
• Showcased efficiency gains, reducing computational cost significantly.

Conclusions:

• The extended embedding scheme provides a computationally efficient route to highly accurate electronic structure calculations for extended systems.
• This approach offers a promising alternative for studying large and complex materials.
• Addresses challenges in disentangling fragment and bath states in embedding theories.