Polarizable Frozen Density Embedding with External Orthogonalization.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Accurately describing electronic properties of molecules on metal clusters is crucial for catalysis and materials science.
• Existing methods like frozen density embedding (FDE) face challenges with strongly interacting systems and computational cost.

Purpose of the Study:

• To develop a novel polarizable subsystem density functional theory (DFT) method.
• To efficiently describe electronic properties of molecules embedded on metal clusters.
• To overcome limitations of existing FDE approaches.

Main Methods:

• Implemented a polarizable subsystem DFT incorporating external orthogonality (EO) via a projection operator.
• Bypassed computationally expensive freeze/thaw (FT) cycles by including a polarization term in the embedding operator.
• Utilized supermolecular basis set calculations for strongly interacting systems.

Main Results:

• The method accurately reproduces ground state densities (within 0.15e) and multipole moments (within 18%) for pyridine, water, and benzene on silver clusters.
• Achieved accurate density embedding through the combination of EO and FT for benchmarking.
• Demonstrated flexibility in using different DFTs for molecular and metallic subsystems, reducing computational cost.

Conclusions:

• The developed polarizable subsystem DFT offers an efficient and accurate approach for electronic structure calculations of molecules on metal surfaces.
• The method enables reliable predictions of molecular properties in complex chemical environments.
• This formalism provides a computationally advantageous alternative for studying molecule-metal interactions.