Benchmarking Density Functionals for Chemical Bonds of Gold.

Area of Science:

• Computational chemistry
• Quantum chemistry
• Materials science

Background:

• Gold is crucial in nanochemistry, catalysis, and electrochemistry.
• Density functional theory (DFT) is widely used for gold bonding studies.
• A systematic accuracy assessment of DFT methods for gold is lacking.

Purpose of the Study:

• To benchmark the accuracy of twelve density functionals for gold bonding.
• To evaluate performance across various gold-containing systems and bond types.
• To identify reliable DFT methods for computational gold chemistry.

Main Methods:

• Benchmarking against 51 experimental bond enthalpies of AuX systems and 7 additional molecules.
• Testing 12 density functionals: meta, hybrid, double-hybrid, dispersion-corrected, and GGA.
• Analyzing bonding from electronegative halides to noble gases, including Au2.

Main Results:

• PBE and TPSS functionals with dispersion correction (PBE-D3, TPSS-D3) showed the smallest numerical errors (0-6 kJ/mol).
• These methods demonstrated minimal bias and halved mean absolute errors compared to B3LYP (23 vs. 45 kJ/mol).
• Dispersion corrections significantly improve accuracy, especially for larger systems like AuXe and AuKr.

Conclusions:

• PBE-D3 and TPSS-D3 are recommended for DFT studies of gold chemistry.
• These functionals provide reliable and accurate results, even with computational cost constraints.
• The findings validate the use of DFT with effective core potentials for gold research.