An efficient localization procedure for large systems using a sequential transformation strategy.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Accurate molecular orbital calculations are crucial for understanding chemical systems.
• Localizing molecular orbitals enhances interpretability and can improve computational efficiency.
• Existing methods for large systems can be computationally intensive.

Purpose of the Study:

• To develop a fast and efficient fragment-based top-down localization scheme.
• To obtain occupied and virtual regionally localized molecular orbitals (RLMOs) for large systems.
• To demonstrate the computational efficiency and accuracy of the new scheme.

Main Methods:

• A fragment-based sequential transformation strategy is employed.
• Singular value decomposition operations are utilized for RLMO construction.
• The scheme is a non-iterative procedure with cubic computational scaling.

Main Results:

• The developed scheme rapidly generates RLMOs for large molecular systems.
• RLMOs exhibit locality comparable to conventional methods.
• The approach is efficient for computing both occupied and virtual RLMOs.

Conclusions:

• The fragment-based top-down localization scheme offers a computationally efficient solution for large systems.
• This method provides accurate and localized molecular orbitals.
• It is a valuable tool for theoretical and computational chemistry research.