Projector-Free Capped-Fragment Scheme within Density Functional Embedding Theory for Covalent and Ionic Compounds.

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Materials Science

Background:

• Quantum-mechanics-(QM)-based simulations are crucial for understanding molecular and material properties.
• Correlated wavefunction (CW) theories offer high accuracy but are computationally expensive for large systems.
• Divide-and-conquer methods partition large systems to manage computational cost.

Purpose of the Study:

• To develop an efficient QM simulation method for large systems incorporating CW theories.
• To introduce a partitioning protocol using capping atoms and density functional embedding theory (DFET).
• To reduce the computational expense of simulating complex chemical systems.

Main Methods:

• Utilized capping atoms to saturate covalent bonds at fragment interfaces.
• Employed density functional embedding theory (DFET) to describe fragment interactions.
• Incorporated an auxiliary fragment to correct for capping group electron density contributions.
• Developed a purely electron-density-dependent embedding potential.

Main Results:

• Demonstrated the utility of the capped-DFET and capped embedded CW method.
• Successfully simulated contrasting systems: an organic molecule and an ionic metal oxide cluster.
• Achieved accurate simulations with reduced computational cost.

Conclusions:

• The capped-DFET method provides a computationally efficient way to apply CW theories to large systems.
• This approach simplifies implementation and reduces the cost of QM simulations.
• The method shows promise for diverse applications in chemistry and materials science.