Self-Consistent Density-Functional Embedding: A Novel Approach for Density-Functional Approximations.

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Materials Science

Background:

• Density Functional Theory (DFT) typically uses energy functionals.
• Accurate mapping of electron density to potential is crucial in DFT.
• Existing methods may struggle with complex electronic structures.

Purpose of the Study:

• To develop a self-consistent density-functional embedding technique.
• To directly target the density-to-potential mapping in DFT.
• To improve the accuracy of Kohn-Sham potentials.

Main Methods:

• Projecting the full system onto smaller, accurately solvable fragments.
• Inverting fragment densities to obtain local potentials.
• Continuously updating the Kohn-Sham potential based on fragment results.

Main Results:

• The technique converges to accurate densities and Kohn-Sham potentials for molecular bond stretching.
• It successfully reproduces known features of the exact exchange-correlation potential.
• Demonstrated accuracy in one and two-dimensional molecular systems.

Conclusions:

• The developed embedding technique offers a promising alternative to standard energy-functional approaches.
• It provides accurate approximations for electronic properties by focusing on density-potential mapping.
• This method advances the capability of DFT for complex systems.