Modeling the MoFe nitrogenase system with broken symmetry density functional theory

Area of Science:

• Computational chemistry
• Bioinorganic chemistry
• Quantum mechanics

Background:

• Molybdenum-iron (MoFe) nitrogenase catalyzes crucial nitrogen (N2) reduction.
• Accurately modeling the spin-polarized iron-molybdenum cofactor (FeMo-co) is computationally challenging.
• Density functional theory (DFT) provides a framework for molecular insights.

Purpose of the Study:

• To enhance DFT for accurate electronic structure calculations of the FeMo-co.
• To demonstrate the utility of broken symmetry DFT (BS-DFT) plus approximate spin projection.
• To provide a theoretical tool for interpreting experimental spectroscopic data.

Main Methods:

• Utilizing broken symmetry DFT (BS-DFT).
• Incorporating approximate spin projection.
• Applying theoretical tools to compute geometries, energies, and redox potentials.

Main Results:

• BS-DFT with spin projection enables reliable computation of key FeMo-co properties.
• This enhanced DFT approach provides quantities relevant to Mössbauer and ENDOR spectroscopies.
• Demonstrated BS-DFT as a powerful complement to experimental studies.

Conclusions:

• BS-DFT plus spin projection is a valuable method for studying MoFe nitrogenase.
• Quantitative quantum chemical theory is essential for deciphering complex bioinorganic systems.
• This approach will increasingly aid research on nitrogenase and similar enzymes.