Survival of the most transferable at the top of Jacob’s ladder: Defining and testing the ωB97M(2) double hybrid density functional

• Published in: The Journal of chemical physics Vol. 148; no. 24; pp. 241736 - 241749
• Main Authors: Mardirossian, Narbe, Head-Gordon, Martin
• Format: Journal Article
• Language: English
• Published: United States American Institute of Physics 28.06.2018; American Institute of Physics (AIP); AIP Publishing LLC
• Subjects: Data analysis; Data points; Density; Electronic structure; Functionals; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Mathematical analysis; Organic chemistry; Outliers (statistics); Perturbation theory; Special Topic: Data-Enabled Theoretical Chemistry
• ISSN: 0021-9606; 1089-7690; 1089-7690
• DOI: 10.1063/1.5025226

A meta-generalized gradient approximation, range-separated double hybrid (DH) density functional with VV10 non-local correlation is presented. The final 14-parameter functional form is determined by screening trillions of candidate fits through a combination of best subset selection, forward stepwise selection, and random sample consensus (RANSAC) outlier detection. The MGCDB84 database of 4986 data points is employed in this work, containing a training set of 870 data points, a validation set of 2964 data points, and a test set of 1152 data points. Following an xDH approach, orbitals from the ωB97M-V density functional are used to compute the second-order perturbation theory correction. The resulting functional, ωB97M(2), is benchmarked against a variety of leading double hybrid density functionals, including B2PLYP-D3(BJ), B2GPPLYP-D3(BJ), ωB97X-2(TQZ), XYG3, PTPSS-D3(0), XYGJ-OS, DSD-PBEP86-D3(BJ), and DSD-PBEPBE-D3(BJ). Encouragingly, the overall performance of ωB97M(2) on nearly 5000 data points clearly surpasses that of all of the tested density functionals. As a Rung 5 density functional, ωB97M(2) completes our family of combinatorially optimized functionals, complementing B97M-V on Rung 3, and ωB97X-V and ωB97M-V on Rung 4. The results suggest that ωB97M(2) has the potential to serve as a powerful predictive tool for accurate and efficient electronic structure calculations of main-group chemistry.