Simple and Efficient Truncation of Virtual Spaces in Embedded Wave Functions via Concentric Localization

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Wave function-in-density functional theory (WF-in-DFT) embedding methods are crucial for accurate molecular simulations.
• High computational cost remains a significant barrier for large-scale WF-in-DFT applications.
• Efficient localization schemes for virtual orbitals are needed to improve computational efficiency.

Purpose of the Study:

• To introduce a novel strategy for generating concentrically local orbitals.
• To reduce the computational expense of WF-in-DFT embedding calculations.
• To provide a method with tunable accuracy for electronic structure calculations.

Main Methods:

• Projection of the virtual space onto atomic orbitals centered on embedded atoms.
• Iterative spanning of the virtual space using a one-particle operator.
• Recursive creation of virtual orbital shells with decreasing correlation energy recovery.

Main Results:

• Demonstrated a significant decrease in computational cost for WF-in-DFT embedding.
• Achieved tunable accuracy by controlling the number of iterative steps.
• Successfully applied the method to model the Menshutkin reaction in a carbon nanotube and the retinal chromophore.

Conclusions:

• The proposed concentrically local orbital strategy effectively reduces computational cost in WF-in-DFT.
• The method offers a balance between accuracy and computational efficiency.
• This approach facilitates the study of larger and more complex chemical systems.