论文标题
合奏的重量依赖性局部相关密度函数函数近似
A weight-dependent local correlation density-functional approximation for ensembles
论文作者
论文摘要
我们报告了一个局部，重量依赖性的相关密度函数函数近似，该近似结合了合奏的密度功能理论（EDFT）的情况。合奏的这种密度功能近似是专门设计的，用于计算总（oliveira-- oliveira-- gok）dft（即用于中性激发的EDFT）中的单一和双重激发，并且可以自然地看作是无用的局部密度近似的自然扩展。基于有限和无限均匀的电子气模型，所得的密度功能近似自动通过其显式的集合重量依赖性纳入了对激发能的臭名昭著的衍生性不连续性贡献。通过计算弱，中间和强相关方案中一维多电子系统中的单一和双电子系统中的单一和双重激发来说明其精度。尽管目前的重量依赖性功能是专门为一维系统设计的，但此处提出的方法是一般的，即直接适用于重量依赖性功能的现实三维系统，例如分子和固体。
We report a local, weight-dependent correlation density-functional approximation that incorporates information about both ground and excited states in the context of density-functional theory for ensembles (eDFT). This density-functional approximation for ensembles is specially designed for the computation of single and double excitations within Gross--Oliveira--Kohn (GOK) DFT (i.e., eDFT for neutral excitations), and can be seen as a natural extension of the ubiquitous local-density approximation in the context of ensembles. The resulting density-functional approximation, based on both finite and infinite uniform electron gas models, automatically incorporates the infamous derivative discontinuity contributions to the excitation energies through its explicit ensemble weight dependence. Its accuracy is illustrated by computing single and double excitations in one-dimensional many-electron systems in the weak, intermediate and strong correlation regimes. Although the present weight-dependent functional has been specifically designed for one-dimensional systems, the methodology proposed here is general, i.e., directly applicable to the construction of weight-dependent functionals for realistic three-dimensional systems, such as molecules and solids.
