Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, 37831, TN, USA.
Department of Materials Science & Engineering, and Institute of Materials Science, University of Connecticut, Storrs, 06269, Connecticut, USA.
Sci Rep. 2017 Mar 3;7:43482. doi: 10.1038/srep43482.
Using the van der Waals density functional with C09 exchange (vdW-DF-C09), which has been applied to describing a wide range of dispersion-bound systems, we explore the physical properties of prototypical ABO bulk ferroelectric oxides. Surprisingly, vdW-DF-C09 provides a superior description of experimental values for lattice constants, polarization and bulk moduli, exhibiting similar accuracy to the modified Perdew-Burke-Erzenhoff functional which was designed specifically for bulk solids (PBEsol). The relative performance of vdW-DF-C09 is strongly linked to the form of the exchange enhancement factor which, like PBEsol, tends to behave like the gradient expansion approximation for small reduced gradients. These results suggest the general-purpose nature of the class of vdW-DF functionals, with particular consequences for predicting material functionality across dense and sparse matter regimes.
使用范德华密度泛函与 C09 交换（vdW-DF-C09），它已被应用于描述广泛的色散束缚系统，我们探索了原型 ABO 体铁电氧化物的物理性质。令人惊讶的是，vdW-DF-C09 对晶格常数、极化和体弹性模量的实验值提供了优越的描述，其准确性与专门为体固体设计的修正 Perdew-Burke-Erzenhoff 泛函（PBEsol）相似。vdW-DF-C09 的相对性能与其交换增强因子的形式密切相关，与 PBEsol 一样，它倾向于对于小的缩减梯度，表现为梯度展开近似。这些结果表明了 vdW-DF 泛函类的通用性质，对于预测密集和稀疏物质状态下的材料功能具有特殊意义。
