Choose Your Level Wisely: Assessing Density Functionals and Dispersion Corrections for Metal Carbonyl Compounds

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Accurate modeling of metal-ligand complexes is crucial for applications in catalysis, materials science, and biochemistry.
• Metal carbonyls, with their varied structures and electronic properties, are important model systems.
• Reliable computational methods are needed to predict their structural and vibrational characteristics.

Purpose of the Study:

• To benchmark seventeen density functionals combined with three dispersion schemes for metal carbonyls.
• To evaluate the accuracy of fifty-four computational approaches in reproducing geometries, structural parameters, and CO stretching frequencies.
• To identify the most accurate and efficient methods for studying manganese(I) and rhenium(I) carbonyls.

Main Methods:

• Systematic evaluation of 54 computational methods, including 17 density functionals and 3 dispersion corrections (D3zero, D3BJ, D4), on 34 Mn(I) and Re(I) carbonyls from the CCDC.
• Assessment of geometries, structural parameters, and CO stretching frequencies.
• Comparison of relative electronic energies with high-level DLPNO-CCSD(T) calculations and analysis of computational cost.

Main Results:

• Hybrid meta-GGA and meta-GGA functionals demonstrated superior performance.
• TPSSh(D3zero) and r2SCAN(D3BJ, D4) were identified as the best performing methods, balancing accuracy and computational efficiency.
• These selected methods provided reliable structural, vibrational, and energetic properties consistent with high-level quantum chemical calculations.

Conclusions:

• Density functional theory (DFT) with appropriate functional and dispersion corrections can accurately model metal carbonyls.
• TPSSh and r2SCAN functionals, especially with D3zero, D3BJ, or D4 dispersion, are recommended for studying Mn(I) and Re(I) carbonyls.
• The findings aid in selecting efficient and accurate computational tools for catalyst design and materials development.