Mardirossian Narbe, Head-Gordon Martin
Department of Chemistry, University of California, Berkeley, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Phys Chem Chem Phys. 2014 Jun 7;16(21):9904-24. doi: 10.1039/c3cp54374a. Epub 2014 Jan 16.
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.
提出了一种具有非局部相关（VV10）的10参数、范围分离混合（RSH）广义梯度近似（GGA）密度泛函。不是统一截断交换、同自旋相关和异自旋相关泛函的B97型幂级数非均匀性校正因子（ICF），而是考虑了高达四阶（m = 4）的线性参数的所有16383种组合。这些泛函分别拟合到一个训练集，并在一个主要测试集上验证所得参数，以识别3种最优的ICF展开式。通过这个过程，发现了在训练集和主要测试集上表现最佳的泛函有7个线性参数，还有来自范围分离和非局部相关的3个额外非线性参数。所得的密度泛函ωB97X-V在一个二级测试集、平行位移的并五苯二聚体以及几个几何数据集上进一步评估。此外，分析并记录了ωB97X-V的基组依赖性和积分网格敏感性，以方便该泛函的使用。
