Embedded-cluster calculations in a numeric atomic orbital density-functional theory framework.

Area of Science:

• Computational chemistry and materials science

Background:

• Quantum mechanics/molecular mechanics (QM/MM) methods are crucial for studying complex systems.
• Integrating advanced electronic structure codes into QM/MM frameworks is essential for improving accuracy.

Purpose of the Study:

• To integrate the all-electron electronic structure code FHI-aims into the ChemShell package.
• To enable solid-state QM/MM calculations using FHI-aims, particularly for hybrid and double-hybrid density functional theory (DFT).

Main Methods:

• Implementation of pseudopotential functionality in FHI-aims to describe cations at the QM/MM boundary.
• Utilizing numeric atomic orbital basis sets for efficient access to exact exchange and second-order perturbation theory.
• Application of the integrated QM/MM approach to model Fe in ZSM-5 zeolites and TiO2 photocatalysis.

Main Results:

• Successful integration of FHI-aims into ChemShell for solid-state QM/MM.
• Demonstrated capability for accurate hybrid and double-hybrid DFT calculations on solid systems.
• Calculated reduction potential of Fe in Fe-ZSM-5 and reaction energy profile for water oxidation at TiO2(110).

Conclusions:

• The developed QM/MM approach provides an efficient and accurate tool for solid-state electronic structure calculations.
• This integration facilitates advanced DFT studies of catalytic processes and materials properties.