DFT-D4 Counterparts of Leading Meta-GGA and Hybrid Density Functionals for Energetics and Geometries

Previously, we introduced DFT-D3(BJ) variants of the B97M-V, ωB97X-V and ωB97M-V functionals and assessed them for the GMTKN55 database [Najibi and Go- erigk, J Chem. Theory Comput. 2018, 14, 5725]. In this study, we present DFT-D4 damping parameters to build the DFT-D4 counterparts of these functionals and assess these in comparison. We extend our analysis beyond GMTKN55 and especially turn our attention to enzymatically catalysed and metal-organic reactions. We find that B97M-D4 is now the second-best performing meta-GGA functional for the GMTKN55 database and it can provide noticeably better organometallic reaction energies com- pared to B97M-D3(BJ). Moreover, the aforementioned DFT-D3(BJ) based functionals have not been thoroughly assessed for geometries and herein we close this gap by analysing geometries of noncovalently bound dimers and trimers, peptide conformers, water hexamers and transition-metal complexes. We find that several of the B97(M)- based methods—particularly the DFT-D4 versions—surpass the accuracy of previously studied methods for peptide conformer, water hexamer, and transition-metal complex geometries, making them safe-to-use, cost-efficient alternatives to the original methods. The DFT-D4 variants can be easily used with ORCA4.1 and above.