Evaluating Transition Metal Barrier Heights with the Latest Density Functional Theory Exchange-Correlation...

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Chemical Physics

Background:

• Accurate prediction of transition metal reaction barrier heights is crucial for understanding chemical reactivity.
• Existing databases and computational methods require rigorous benchmarking for reliability.

Purpose of the Study:

• To present a new database of transition metal reaction barrier heights (MOBH35).
• To evaluate the performance of various density functional theory (DFT) exchange-correlation functionals against high-level benchmark calculations.
• To identify accurate and reliable DFT functionals for predicting reaction barriers in transition metal chemistry.

Main Methods:

• Calculation of benchmark energies using coupled-cluster theory with perturbative doubles and triples corrections (DLPNO-CCSD(T)) extrapolated to the complete basis set limit.
• Evaluation of multiple DFT functionals, including hybrid and double-hybrid types, using the def2-TZVPP basis set.
• Statistical analysis of mean absolute deviations (MAD) between DFT predictions and benchmark energies.

Main Results:

• The MOBH35 database provides benchmark energies for transition metal reactions.
• Several hybrid functionals, including ωB97M-V, ωB97M-D3BJ, ωB97X-V, and revTPSS0-D4, demonstrated high accuracy (MAD ≤ 2.2 kcal/mol).
• Double-hybrid functionals B2K-PLYP and revDOD-PBEP86-D4 also showed excellent performance (MAD ≤ 1.8 kcal/mol) but with higher computational cost.

Conclusions:

• The MOBH35 database serves as a valuable resource for benchmarking DFT functionals.
• ωB97M-V, ωB97M-D3BJ, ωB97X-V, and revTPSS0-D4 are recommended DFT functionals for transition metal reaction barriers.
• Double-hybrid functionals offer high accuracy but require careful consideration of computational expense.