ωB97X-V: A 10-parameter, range-separated hybrid, generalized gradient approximation density functional with nonlocal correlation, designed by a survival-of-the-fittest strategy

Abstract

A 10-parameter, range-separated hybrid (RSH), generalized gradient approximation (GGA) density functional with nonlocal correlation (VV10) is presented. Instead of truncating the B97-type power series inhomogeneity correction factors (ICF) for the exchange, same-spin correlation, and opposite-spin correlation functionals uniformly, all 16,383 combinations of the linear parameters up to fourth order (m = 4) are considered. These functionals are individually fit to a training set and the resulting parameters are validated on a primary test set in order to identify the 3 optimal ICF expansions. Through this procedure, it is discovered that the functional that performs best on the training and primary test sets has 7 linear parameters, with 3 additional nonlinear parameters from range-separation and nonlocal correlation. The resulting density functional, ωB97X-V, is further assessed on a secondary test set, the parallel-displaced coronene dimer, as well as several geometry datasets. Furthermore, the basis set dependence and integration grid sensitivity of ωB97X-V are analyzed and documented in order to facilitate the use of the functional.

How Accurate Are the Minnesota Density Functionals for Noncovalent Interactions, Isomerization Energies, Thermochemistry, and Barrier Heights Involving Molecules Composed of Main-Group Elements?

“…[122][123][124] Indeed, 12 of the 14 functionals have EBL RMSDs larger than 0.1Å. MN15-L and MN15 perform well for the rare-gas dimers, primarily because their training set includes a handful of data points from several rare-gas dimer PECs.…”

Fast, accurate evaluation of exact exchange: The occ-RI-K algorithm

“…32 Functionals trained close to the basis set limit yield significantly inferior performance in smaller basis sets. 13,33,34 This paper attempts to make progress on the challenging problem of constructing the K matrix in these large basis sets.…”

“…The importance of including exact exchange was initially recognized by Becke,7,8 and exact exchange has since become a core component of a huge number of widely used modern density functionals. [9][10][11][12][13] Unfortunately, exact exchange requires the computation of the numerous and expensive four-center two-electron repulsion integrals (ERIs), (µλ|νσ) =   dr 1 dr 2 φ * µ (r 1 )φ λ (r 1 )r −1 12 φ ν (r 2 ) * φ σ (r 2 ),…”

Formation of chlorobenzenes by oxidative thermal decomposition of 1,3-dichloropropene

“…Mardirossian and HeadGordon [26] have recently shown that M06-2X provides good overall performance for reaction thermochemistry. Nevertheless, to ensure this is the case in the current context, we compare M06-2X-calculated kinetic and thermodynamic parameters with G3MP2B3 [27] and experimental values (see Tables S1 and S2 in the Supporting Information).…”

“…A number of previous investigations have shown that small aromatic molecules can form via cyclisation of unsaturated hydrocarbons (e.g., 1,3,5-hexatriene [28], hexachloropropene [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]). …”